Trimaran - Especially Searunner - Owners

[Mark Johnson]

Originally Posted by owly

Only weighing the boat in some way will tell the story. Anything else is just speculation I would say.

H.W.

In a small cat, you WANT less than standing headroom in the bridge deck, in order to have sufficient bridge clearance. Low windage is paramount, as is a low center of gravity, and full visibility forward. YOU MUST HAVE KEELS, CB, OR DAGGERBOARDS, if you want to go to windward. Nothing else works well at all!

In Searunners, the elbows is the ama keel, where it meets it’s transom. Ideally, it would be several inches out, but NEVER submersed with the boat trimmed level.

Looking at where she floats says it all, more than scales.

Even with a 37, I would NEVER carry more than 100 pounds of tools! Go through your wrench roll, and take every wrench that has no corresponding bolt on the boat, for example.

In books, if they have entire duplicate chapters in Japanese, tear them out!

Take only what you need, and provision less but more often. Freeze dried packs can make up months of “emergency” rations.

We carried what we needed, but NOTHING we did not, and always bought the lightest version of everything we have on board!

One must totally avoid the monohull mentality, and think like a backpacker, who ALSO has all that he needs.

If you need way more payload, a fatter hulled Cross may be better?

In Searunners, CHECK THE CB and trunk areas CAREFULLY, first!

[owly]

Mark:
Thanks for the clarification on "elbows". I don't believe I suggested that the lack of standing headroom was a negative on the 860, it is one of the things that attracts me.... The fact that the designer went with high bridge deck clearance and low headroom, maintaining low windage......... all the right choices in my opinion. 58 inches at the high point of the gently curved roofline, the whole thing is very streamlined and low.
Kohler has done a lot of work with anti vortex panels and they work, at least the designer and owners say they do. Keels have the potential to "trip" a multihull, centerboards require a heavy trunk that takes up interior space, and dagger boards which cannot fold back like a centerboard are subject to striking ground and breaking or even damaging the hull. Anti vortex panels ONLY work with flat bottoms. Flat bottoms equate to a bit more wetted surface, but to simpler construction, and elimination of a centerboard and trunk means savings in weight and drag. AV panels are small "winglets", and are passive........ You don't raise or lower them, and they don't increase draft. Flat bottom also means the cabin sole can be the actual bottom, or much closer to it.... shallow or no bilge, which equates to less cabin height in the hulls, more streamlined roofline, and also more displacement per inch of immersion. Very narrow near the bows, they are not going to be subject to pounding as on a flat bottom dinghy. It all looks good to me. Perhaps too good to be true.

https://www.duckworksbbs.com/product-p/bk-kd860-id.htm
KD860page

The one thing it lacks is a forward inside watch keeping station with 180+ deg panoramic view, but that would not be too much of a challenge to do without destroying the appearance completely. A thick plexiglass bubble could be blown similar to what is used on many home built aircraft that would contour in decently. It would be in one of the forward berth areas where the roofline slopes down to the front. I hardly need 2 doubles

H.W.

Originally Posted by Mark Johnson

In a small cat, you WANT less than standing headroom in the bridge deck, in order to have sufficient bridge clearance. Low windage is paramount, as is a low center of gravity, and full visibility forward. YOU MUST HAVE KEELS, CB, OR DAGGERBOARDS, if you want to go to windward. Nothing else works well at all!

In Searunners, the elbows is the ama keel, where it meets it’s transom. Ideally, it would be several inches out, but NEVER submersed with the boat trimmed level.

Looking at where she floats says it all, more than scales.

Even with a 37, I would NEVER carry more than 100 pounds of tools! Go through your wrench roll, and take every wrench that has no corresponding bolt on the boat, for example.

In books, if they have entire duplicate chapters in Japanese, tear them out!

Take only what you need, and provision less but more often. Freeze dried packs can make up months of “emergency” rations.

We carried what we needed, but NOTHING we did not, and always bought the lightest version of everything we have on board!

One must totally avoid the monohull mentality, and think like a backpacker, who ALSO has all that he needs.

If you need way more payload, a fatter hulled Cross may be better?

In Searunners, CHECK THE CB and trunk areas CAREFULLY, first!

[Mark Johnson]

Originally Posted by owly

Mark:
Thanks for the clarification on "elbows". I don't believe I suggested that the lack of standing headroom was a negative on the 860, it is one of the things that attracts me.... The fact that the designer went with high bridge deck clearance and low headroom, maintaining low windage......... all the right choices in my opinion. 58 inches at the high point of the gently curved roofline, the whole thing is very streamlined and low.
Kohler has done a lot of work with anti vortex panels and they work, at least the designer and owners say they do. Keels have the potential to "trip" a multihull, centerboards require a heavy trunk that takes up interior space, and dagger boards which cannot fold back like a centerboard are subject to striking ground and breaking or even damaging the hull. Anti vortex panels ONLY work with flat bottoms. Flat bottoms equate to a bit more wetted surface, but to simpler construction, and elimination of a centerboard and trunk means savings in weight and drag. AV panels are small "winglets", and are passive........ You don't raise or lower them, and they don't increase draft. Flat bottom also means the cabin sole can be the actual bottom, or much closer to it.... shallow or no bilge, which equates to less cabin height in the hulls, more streamlined roofline, and also more displacement per inch of immersion. Very narrow near the bows, they are not going to be subject to pounding as on a flat bottom dinghy. It all looks good to me. Perhaps too good to be true.

https://www.duckworksbbs.com/product-p/bk-kd860-id.htm
KD860page

The one thing it lacks is a forward inside watch keeping station with 180+ deg panoramic view, but that would not be too much of a challenge to do without destroying the appearance completely. A thick plexiglass bubble could be blown similar to what is used on many home built aircraft that would contour in decently. It would be in one of the forward berth areas where the roofline slopes down to the front. I hardly need 2 doubles

H.W.

I had a 30” plexiglass hemisphere steering station on my SC 28, and it was GREAT!

I have friends in Australia who circumnavigated over 10 years in a 34’ cat with < 5’ headroom, and this allowed good wing clearance AND low cog and windage. Their EXPENSIVE roller fueling boom, made it a true sea boat! It was so easily reefed.

Multihulls need something deep to get below the turbulent water at the top, if they really want good windward performance.

They will not trip over them unless they are down in a beam gale, with full sail, and the fact that they “could” is why they create lateral resistance. Anything that allows the boat to slip sideways, can not also keep it from side slipping when hard on the wind, like my Wharram used to do, or, Hobie 16s!

“Some” Boats without cbs or daggerboards or a generous keel “point” to windward just fine, but when you look at your track, it is quite poor, compared to a boat with a CB like ours, which is 7’ deep, they do not GO to windward!

We can make good through 90 degree tacks, 45 to port 45 to starboard, “made good”.

If you do not care about this, and don’t mind your boat actually making good maybe 55 or 60 degrees from the apparent Wind, then the simplicity is great. This is the Wharram cat trade off, and they are usually trade wind sailed, off the wind, for this reason.

Vortex generators and such were around 40 years ago, with similar claims. They might help a bit, but still, no comparison.

If you want a boat to really sail to windward, the BEST is a boat with a huge daggerboard (but very VULNERABLE), followed closely by a huge crnterboard held down with a fuse so it can kick up (NOT so vulnerable), followed by a deep keel (too deep a permanent draft), followed by a long shallow keel like SR cats. In that order.

If ya wanna go to weather, ya gotta have lateral resistance, and lots of it!

[owly]

Mark:
I like it............ Though I had in mind a more streamlined bubble rather than a hemisphere. Blowing such a bubble is not a huge challenge, lots of home aircraft builders have blown their own. In the case of the KD 860, it would be going into a surface that was sloping downward toward the bow, and it might bear some resemblance to this canopy

Imagine that sort of canopy on the leading edge of this boat that has almost no forward visibility............ hope the file comes through..... It obviously would need to be custom designed for the application. Such a bubble might also make the forward portion of the Marples 35 a much more useful area. The lack of standing room and entire lack of any forward visibility from inside the boat make the 35 an undesirable boat, though that sloping forward deck looks racy. I personally would like to have a seating position at the aft edge or in the doorway to the dressing room that would give me some forward view.
Note that Pete Hill's Oryx which you can find by googling it, has a bubble similar to yours in the wing deck cabin where you can stand and look out.

Any live aboard voyager is going to spend far more time at anchor or on a mooring than crossing oceans and sailing unless he simply sets out to live in the open sea, and I've only ever heard of one person doing that. This makes a catamaran a better choice in terms of living space. One solution to the low bridge deck cabin head room is a pop top..... I've seen this on several cats. It's as good idea in terms of standing head room and ventilation, yet it could be closed when you need it closed. The challenge is making something like this water tight, but that's not too much of a challenge.

H.W.

Originally Posted by Mark Johnson

I had a 30” plexiglass hemisphere steering station on my SC 28, and it was GREAT!

I have friends in Australia who circumnavigated over 10 years in a 34’ cat with < 5’ headroom, and this allowed good wing clearance AND low cog and windage. Their EXPENSIVE roller fueling boom, made it a true sea boat! It was so easily reefed.

Multihulls need something deep to get below the turbulent water at the top, if they really want good windward performance.

They will not trip over them unless they are down in a beam gale, with full sail, and the fact that they “could” is why they create lateral resistance. Anything that allows the boat to slip sideways, can not also keep it from side slipping when hard on the wind, like my Wharram used to do, or, Hobie 16s!

“Some” Boats without cbs or daggerboards or a generous keel “point” to windward just fine, but when you look at your track, it is quite poor, compared to a boat with a CB like ours, which is 7’ deep, they do not GO to windward!

We can make good through 90 degree tacks, 45 to port 45 to starboard, “made good”.

If you do not care about this, and don’t mind your boat actually making good maybe 55 or 60 degrees from the apparent Wind, then the simplicity is great. This is the Wharram cat trade off, and they are usually trade wind sailed, off the wind, for this reason.

Vortex generators and such were around 40 years ago, with similar claims. They might help a bit, but still, no comparison.

If you want a boat to really sail to windward, the BEST is a boat with a huge daggerboard (but very VULNERABLE), followed closely by a huge crnterboard held down with a fuse so it can kick up (NOT so vulnerable), followed by a deep keel (too deep a permanent draft), followed by a long shallow keel like SR cats. In that order.

If ya wanna go to weather, ya gotta have lateral resistance, and lots of it!Attachment 159459

[Mark Johnson]

Originally Posted by owly

Mark:
I like it............ Though I had in mind a more streamlined bubble rather than a hemisphere. Blowing such a bubble is not a huge challenge, lots of home aircraft builders have blown their own. In the case of the KD 860, it would be going into a surface that was sloping downward toward the bow, and it might bear some resemblance to this canopy

Imagine that sort of canopy on the leading edge of this boat that has almost no forward visibility............ hope the file comes through..... It obviously would need to be custom designed for the application. Such a bubble might also make the forward portion of the Marples 35 a much more useful area. The lack of standing room and entire lack of any forward visibility from inside the boat make the 35 an undesirable boat, though that sloping forward deck looks racy. I personally would like to have a seating position at the aft edge or in the doorway to the dressing room that would give me some forward view.
Note that Pete Hill's Oryx which you can find by googling it, has a bubble similar to yours in the wing deck cabin where you can stand and look out.

Any live aboard voyager is going to spend far more time at anchor or on a mooring than crossing oceans and sailing unless he simply sets out to live in the open sea, and I've only ever heard of one person doing that. This makes a catamaran a better choice in terms of living space. One solution to the low bridge deck cabin head room is a pop top..... I've seen this on several cats. It's as good idea in terms of standing head room and ventilation, yet it could be closed when you need it closed. The challenge is making something like this water tight, but that's not too much of a challenge.

H.W.

Yep, I recently surveyed a very nifty pop top cat that works well if you never expect green water over the top. Thing is, you still need screens and to close it at night, to keep the moist air out. We find, even in the tropics, that it is not too hot at night, it’s too damp out.

Advantage of a hemisphere is that they are cheep, and commercially available. They fit on flat hatch tops too!

On the CC 35 tri (center cockpit), it would not benefit, IMO, from a large amount of visibility forward, because you hardly ever go there to the forward cabin at sea! A nice hard dodger, however, is as good as gold! THIS is where you want to be at sea, unless you are totally immune to sea sickness.

The axis of gyration on this and our SR34 is aft of center, so that is the place to be at sea. When beating hard to windward, in a gale, we sleep on a mattress in the sterncastle floor, wedged in with pillows.

The headroom in the CC35 vanity is not much of an issue at sea, IMO, because, except off the wind, you seldom go up there, except to brush your teeth or use the head. No need to stand.

As a full time liveaboard, it is an inconvenience,
And there may be a solution, but the large canopy is probably not it, if aesthetics and functionality matter.

I drew my enclosure and hard dodger FIRST, over a hundred times, spanning years, and THEN made the rig match the cockpit setup!

I am sure John Marple’s has considered a lot of options, and HE would know what will or will not work up there, best.

I suggest you talk to him about it before considering raising the vanity.

Remember, access forward, QUICKLY, in an emergency at the bow, is part of the equation.

[Cavalier MK2]

Jim Brown ran me off a bunch of plan sheets for the Brown 41 once when I was looking at one to do the survey. It is the predecessor to the Searunners and looks like them but with a ketch rig and different beams and hull shapes. The center cockpit and cabin profile is there. It has a neat additional forward wheel steering station and the nav table up front so you can look out the front cabin window and drive.

A quick thought about standing headroom in the head. If you have a composting toilet with a urine diverter it has to be used sitting down in order to work. You got to keep 1 and 2 separate to avoid a smelly non composting mess. So sitting headroom only makes this happen for the guests that tend to forget.

[owly]

Mark:
I consider the low clearance in the dressing room a liability.... period, and as my intent is to us a boat as a live aboard voyager / cruiser, realistically I want standing head room there. As it is, it's suitable as a short term weekender / coastal sailor only in my opinion because of this, or a competition boat. The forward area is valuable space that has been compromised in favor of a sleek appearance in my opinion. Most cruisers spend far more time at anchor or on a mooring in various places than at sea. This leaves only one completely indoor area with standing head room, the galley. While your point is well taken about motion, it's hardly the only consideration.

H.W.

Originally Posted by Mark Johnson

Yep, I recently surveyed a very nifty pop top cat that works well if you never expect green water over the top. Thing is, you still need screens and to close it at night, to keep the moist air out. We find, even in the tropics, that it is not too hot at night, it’s too damp out.

Advantage of a hemisphere is that they are cheep, and commercially available. They fit on flat hatch tops too!

On the CC 35 tri (center cockpit), it would not benefit, IMO, from a large amount of visibility forward, because you hardly ever go there to the forward cabin at sea! A nice hard dodger, however, is as good as gold! THIS is where you want to be at sea, unless you are totally immune to sea sickness.

The axis of gyration on this and our SR34 is aft of center, so that is the place to be at sea. When beating hard to windward, in a gale, we sleep on a mattress in the sterncastle floor, wedged in with pillows.

The headroom in the CC35 vanity is not much of an issue at sea, IMO, because, except off the wind, you seldom go up there, except to brush your teeth or use the head. No need to stand.Attachment 159493

As a full time liveaboard, it is an inconvenience,
And there may be a solution, but the large canopy is probably not it, if aesthetics and functionality matter.

I drew my enclosure and hard dodger FIRST, over a hundred times, spanning years, and THEN made the rig match the cockpit setup!

I am sure John Marple’s has considered a lot of options, and HE would know what will or will not work up there, best.

I suggest you talk to him about it before considering raising the vanity.

Remember, access forward, QUICKLY, in an emergency at the bow, is part of the equation.

[smj]

Originally Posted by owly

Mark:
I consider the low clearance in the dressing room a liability.... period, and as my intent is to us a boat as a live aboard voyager / cruiser, realistically I want standing head room there. As it is, it's suitable as a short term weekender / coastal sailor only in my opinion because of this, or a competition boat. The forward area is valuable space that has been compromised in favor of a sleek appearance in my opinion. Most cruisers spend far more time at anchor or on a mooring in various places than at sea. This leaves only one completely indoor area with standing head room, the galley. While your point is well taken about motion, it's hardly the only consideration.

H.W.

I guess I'm a little confused. In the post about the Kohler catamaran you stated this:
Mark:
Thanks for the clarification on "elbows". I don't believe I suggested that the lack of standing headroom was a negative on the 860, it is one of the things that attracts me.... The fact that the designer went with high bridge deck clearance and low headroom, maintaining low windage......... all the right choices in my opinion. 58 inches at the high point of the gently curved roofline, the whole thing is very streamlined and low.
Yet you don't seem to care for the streamlined effect which creates low headroom and low windage in the Marples designed CC 35, which would only affect the dressing room?

[Mark Johnson]

Originally Posted by owly

Mark:
I consider the low clearance in the dressing room a liability.... period, and as my intent is to us a boat as a live aboard voyager / cruiser, realistically I want standing head room there. As it is, it's suitable as a short term weekender / coastal sailor only in my opinion because of this, or a competition boat. The forward area is valuable space that has been compromised in favor of a sleek appearance in my opinion. Most cruisers spend far more time at anchor or on a mooring in various places than at sea. This leaves only one completely indoor area with standing head room, the galley. While your point is well taken about motion, it's hardly the only consideration.

H.W.

Yep, for full time liveaboard, over years, our SR34 is a much bigger boat, with far more storage, flat decks to work on, etc...

If you listen to the last few pod casts with Jim Brown (OUTRIG), first he gives HIS take, in compairing the CC35 to the SR34. Later, in the next pod cast, his lovely wife JoAnna reads out a message I sent in on the subject...

Good stuff.

[owly]

Originally Posted by smj

I guess I'm a little confused. In the post about the Kohler catamaran you stated this:
Mark:
Thanks for the clarification on "elbows". I don't believe I suggested that the lack of standing headroom was a negative on the 860, it is one of the things that attracts me.... The fact that the designer went with high bridge deck clearance and low headroom, maintaining low windage......... all the right choices in my opinion. 58 inches at the high point of the gently curved roofline, the whole thing is very streamlined and low.
Yet you don't seem to care for the streamlined effect which creates low headroom and low windage in the Marples designed CC 35, which would only affect the dressing room?

There is a huge difference between a cat with two hulls, each of which is close to the length of the Marples, and each of which has standing head room throughout most of those hull, and less than standing height ONLY in the saloon on the bridge deck and the berth area forward, and in most builds has two companionways, each with a sliding hatch, and the Marples that has only one small area inside where you can stand. In the Searunners, that space is far from just a place to brush your teeth, it really is intended to be an actual dressing room, and that has value.
There really is no comparison between the cat I mentioned and the Marples. I merely brought up the Marples because there is one nearly complete not far away that caught my interest, and a well built project at a decent price can be a better option than a boat that's been in the water for 20-30 years.
The only way I could swing a cat that meets my criteria would be to build, and I'm not going to make that commitment........ I want to sail, not build.

I'm in fact toying with options......... what I'd like to have, and what I can justify and/or afford, what makes sense, and what does not. The Searunners best meet my criteria, budget, and time.

H.W.

[owly]

Originally Posted by Mark Johnson

Yep, for full time liveaboard, over years, our SR34 is a much bigger boat, with far more storage, flat decks to work on, etc...

If you listen to the last few pod casts with Jim Brown (OUTRIG), first he gives HIS take, in compairing the CC35 to the SR34. Later, in the next pod cast, his lovely wife JoAnna reads out a message I sent in on the subject...

Good stuff. Attachment 159509

I heard the first, but not the second.....

[smj]

Originally Posted by owly

There is a huge difference between a cat with two hulls, each of which is close to the length of the Marples, and each of which has standing head room throughout most of those hull, and less than standing height ONLY in the saloon on the bridge deck and the berth area forward, and in most builds has two companionways, each with a sliding hatch, and the Marples that has only one small area inside where you can stand. In the Searunners, that space is far from just a place to brush your teeth, it really is intended to be an actual dressing room, and that has value.
There really is no comparison between the cat I mentioned and the Marples. I merely brought up the Marples because there is one nearly complete not far away that caught my interest, and a well built project at a decent price can be a better option than a boat that's been in the water for 20-30 years.
The only way I could swing a cat that meets my criteria would be to build, and I'm not going to make that commitment........ I want to sail, not build.

I'm in fact toying with options......... what I'd like to have, and what I can justify and/or afford, what makes sense, and what does not. The Searunners best meet my criteria, budget, and time.

H.W.

We have owned quite a few cruising catamarans and only 2 had full standing headroom throughout for me. I'm tallish and the lack of headroom has never really bothered me. We currently own a Marples designed Searunner 38 catamaran that has 5'+ headroom in the salon and what would be standing headroom for most people in the hulls. I'm sure for quite a few people the lack of headroom wouldn't do, but for me the trade of is no bridgedeck pounding and a boat that performs very well. BTW, I really like the looks of the Kohler 860.

[Mark Johnson]

Originally Posted by owly

There is a huge difference between a cat with two hulls, each of which is close to the length of the Marples, and each of which has standing head room throughout most of those hull, and less than standing height ONLY in the saloon on the bridge deck and the berth area forward, and in most builds has two companionways, each with a sliding hatch, and the Marples that has only one small area inside where you can stand. In the Searunners, that space is far from just a place to brush your teeth, it really is intended to be an actual dressing room, and that has value.
There really is no comparison between the cat I mentioned and the Marples. I merely brought up the Marples because there is one nearly complete not far away that caught my interest, and a well built project at a decent price can be a better option than a boat that's been in the water for 20-30 years.
The only way I could swing a cat that meets my criteria would be to build, and I'm not going to make that commitment........ I want to sail, not build.

I'm in fact toying with options......... what I'd like to have, and what I can justify and/or afford, what makes sense, and what does not. The Searunners best meet my criteria, budget, and time.

H.W.

In building either, a complete hull and deck is only about 35 to 40% of the completely outfitted boat.

The cat has more sitting room in the saloon, but a SR34 OR CC35 has a wonderful cozy sterncastle for 4 to eat.

The CC35 might get small for full time liveaboard, but when you consider a 35’ cat, IF it had the same amount of big bulky gear that I mentioned earlier, (awnings, SCUBA, fenders, ob motor, etc), half of it’s interior would be occupied!

The CC35 is more of a sea boat, and tighter winded I assume, and you CAN stand in the front bunk area or cockpit as well.

With a dodger connected to the Bimini top, the cockpit is a third cabin.
When facing the wind, we can leave the aft companionway hatch open in a light rain.

The CC is a really nice boat, very pretty to my eye, but still, small as a full time liveaboard.

Compared to the cat, envision where ALL of that stuff, plus cloths, tankage, food, tools, dinghy, 4 anchors, spear guns, fishing rods, spinnaker, etc, is going to fit.

On a trimaran, much of it, up to 200 lbs each side, goes in the amas, where stinky stuff is no issue.

Personal choices...

[Buzzman]

That Kohler boat ;looks like it's compromised on the under bridgedeck clearance also, less than 2ft laden on on or below marks.

Listen / read what designers like Jim have to say about clearance less than 3ft.

And ship plenty of Aspirin - for the pounding....

[owly]

None of the small cats have as much bridge deck clearance as one would like. This is mitigated to a significant extent by the fact that the bridge deck begins far back, and the forward edge curves upward. It's kind of a no win situation. You can't have adequate bridge deck clearance, low profile / low windage, and decent head room on the bridge deck. It's an insoluble problem. For a cat to really work out in all respects it needs to be about 45+ feet long. Having the capacity of two full load bearing hulls plus bridge deck space is attractive, at least when in port or at anchor, which is where most boats spend most of their time. A trimaran is like half a cat with two outriggers, or a cat is like two trimaran main hulls joined together. In truth an open bridge deck as Warram used is the only realistic solution to the bridge deck clearance / windage issue. Imagine two Searunner 31 hulls joined together as a cat, or trying to make a bridge deck cabin that spanned the wings. Trimaran designers from the start recognized the wings as not being a "habitable" part of the hull. Catamaran designers are constantly trying to overcome the clearance / standing height / windage equation, and always will be. Interestingly NOBODY lists the bridge deck clearance, loaded or empty in their cat specifications. Measuring on paper based on a diagram that shows waterline, the KD860 only has about 20" of bridge deck clearance. Richard Woods's designs look to be about the same if you lop off the nacelle that hangs down to give standing head room in small areas.

I wonder what the actual loaded bridge deck clearance (min) is on a Searunner 34 or 37? I don't have one to look at.

H.W.

Originally Posted by Buzzman

That Kohler boat ;looks like it's compromised on the under bridgedeck clearance also, less than 2ft laden on on or below marks.

Listen / read what designers like Jim have to say about clearance less than 3ft.

And ship plenty of Aspirin - for the pounding....