Trimaran - Especially Searunner - Owners

[Roy M]

That looks like a pretty hard chine in the background. Is that better than the soft chine of the Searunners?

[Boatguy30]

I'm not sure there is much difference. The panels all meet in fairly tight wood to wood joints then are glassed inside and out. I personally feel this makes for a better joint. Pretty much the same as a searunner ama ends up. I guess it's maybe a tiny bit more wetted surface?

[slowbat]

Has anyone tried Easypoxy one part paint?

Second topic: Running Backstays
What is the process for using them? My 31 had a fractional rig, but my 25 has a masthead rig with running backstays, how will this increase the mast camber?

I have yet to erect the mast, so I'm not sure if it also has a fixed backstay to the main hull, and two more runners to the aft outer aka's. Is this just to make boom room running down wind?

Third topic: Brown designed wind vane
I'm looking for parts if you have any you would like to sell, shoot me a PM

[Mark Johnson]

THE VARDO IS SEARUNNER-LIKE???

About Jim Brown's version of a "catamaran", IF he designed them... He "did" design them, along with John Marples.

Building of a Searunner 36' Catamaran - YouTube

Imo, Searunner Cats are quite a bit different in concept from the Woods Vardo. For example: The Searunner cats are constructed without stringers, of CC panels that are initially stitched together. The accommodations are totally within the walkover hull cabins, (like the tris), except they may have athwartship double bunks forward, that extend into the low profile wing area, with the dinette & opposite hull's nav areas being similar.

Their is usually just a bimini top, (perhaps with a dodger), like in many commercial "cattlemaran" applications, or to make a cruiser version... they have a hard top with windshield, that is low profile and open in the back. It is basically a light weight cockpit enclosure, not a bridge deck cabin.

The LR is provided by long low profile keels, rather than CBs or Daggerboards, so it readily takes to the bottom.

Also... The fractional rig is very stout and very simple, as is the entire structure.

Even with a light/low hardtop version... The extremely low COG and low windage craft, is a super seaworthy "pickup truck" among catamarans. It does have far less creature comfort than most full bridge deck cats, and perhaps less windward ability than "some" high performance daggerboard cats, but it is an extension of the SR tri concept. They do need to be longer than some designs, for sufficient room.

If I were to build a catamaran for world cruising, a "cruising version" of the SR 40 might well be my choice. It would, however, be far more expensive than the 34' Vardo, due to the SR being so much larger a boat.
IF the SR 40 were proportionately scaled down to the size of Jeff's Vardo, it would be small indeed!

I'm not saying I don't like the Vardo, btw, I actually do. It packs in as much accommodation into its WL length as is practical, without giving up heavy weather seaworthiness, as so many similar sized production cats do. It is probably not as seaworthy as say... the SR 34 tri is, but I wouldn't hesitate to cruise on it. Bridge decked cats like this do have the advantage of not having a "wet walkover" between separate cabins, and can presumably accommodate a light weight dinghy in davits. Nice features!

M.

[Boatguy30]

Not to expound on this much further, BUT if Jim were to design a MODERN equivalent family cruiser/ truckster to the SR 37 is would surely be a bridgedeck cat. I realize he and John have done several cats, but they all seem to be the day charter open type cat and I really don't think many have been built as family cruising boats.

Anyhow, the concepts are very much the same. The main reason it seems it took so long to evolve is that people were just not willing to make cats wide enough 30 years ago. The Vardo is only 1' narrower than the SR 34 and Richard actually would have made it a bit wider had it not been for my building space.

Also, the Easypoxy is Ok. I used the light tan and had problems with it chaulking badly after 18 months on a hard bimini. Would like to hear more about the "Nano" tech paint. It makes me think of the "space age" TV infomercials. Very exciting!

[Randy]

I had used Easypoxy some time ago and liked it. Easy to "roll and tip" but I do t think its a true epoxy and won't provide the service life of a 2 part.I'll assume you have a cutter rig setup? My general practice was if using the staysail, the windward runner would be set. The runners are set at the same mast point as the inner forestay and counter that force.

[Mark Johnson]

Dan,

REGARDING EASYPOXY:
I use EasyPoxy "semi-gloss white" EVERYWHERE down below on Delphys, and painted my first cruising boat with it, 37 years ago. Inside, it holds up fine for many years, and is incredibly smooth to apply with a brush. On the "outside" of the boat, IF it is lived on and cruised hard in a harsh tropic environment. I'd give it about a year... two at best. I know of no one part paints that will last longer, however, in the same full time cruising application.

RIGS:
I never knew of a fractionally rigged SR 31, Hmmm? Anyway... Your 25 is a masthead rig, so is presumably rigged as a cutter as well. The staysail stay and runners can both be in the "stored position" when sailing with a genny as a sloop. When the wind picks up, and you hank on a staysail, then you rig up the runners in order to oppose the forces created by the staysail stay. Unless it's blowing a gale, it may not be necessary to use them well off the wind, or just the windward runner may be sufficient. This would allow more "boom out" on the leeward side, than if both runners are rigged up.
THEY DO, UNFORTUNATELY, RESTRICT THE BOOM'S ANGLE when both are rigged up, this is why my runner chainplates were moved one station forward...

The runners are not for inducing mast bend, they are for preventing it.

BACKSTAY/S:
You should have a single backstay, that comes down to a a bridle fixed to chainplates on the transom. There should be NO runners other than the ones that are temporarily rigged up to oppose the staysail stay, and attach to the sides of the amas, about 80% aft. (Meaning...None from the mast head to the ama transoms)

WINDVANE:
John M can shoot you the details for the parts that you need, to have one custom made there. I doubt that another person's XYZ part would do you much good. These things are "similar", but custom, so will vary.

If it were me, I'd go with a small electric tiller pilot, instead. To save on amps... IF you have the trim tab already, (and I assume you do), the autopilot can attach to the trimtab, rather than the tiller itself. This is more complicated to engage & disengage, so more of a "cruising" only concept. Otherwise, for casual cruising/sailing, just hook it to the tiller. These things use very little power, and unlike windvanes, they keep you on a compass course, rather than a relative bearing to the wind. (This matters near shore)! Also, unlike windvanes, they work down wind, or motoring in a calm.

Some well known folks, like Mark Hassle, had great success with the SR windvane, but most cruisers, (including me), found them to be a big disappointment.

If you really want a windvane, the "lay over concept" models work better... but at MANY times the price of a tiller mounted auto pilot.

Good luck with it,
Mark

[Mark Johnson]

SEARUNNER CATAMARANS:
In case my point about "what Jim & John would have done" was lost, I'll clairify... Neither Jeff nor I have any idea, (unless he's clairvoyant)? It would probably depend on who the plans were drawn for and the context. I simply pointed out that they already have designed some beautiful cruising cats. They are indeed, more often than not, seen in the charter trade. Businesses are the ones with the bucks for big cats...

BRIDGE DECK CABINS:
They have in fact, put a full height bridge deck cabin on some of them, but certainly not on a 34'er!
SR 34 Tris like ours, on the other hand, have circumnavigated several times. In fact, a friend of mine owned one next to me in the boatyard, that had done it WITH kids onboard, by way of Cape Horn! (I wouldn't try this in a Vardo, or any other standard 34' cat)... While it might be possible on such a 34' X 6' 2" headroom bridge deck cabin cat, IF you survived, it would be a stunt. No matter the designer, you can't reach the optimal high wing clearance, with low COG and low windage (in cats), until they get much longer than 34'.

This is not true of the SR 34 tri. They have lower windage, and a much lower COG. Bottom line is... that Searunners are seaworthy to a degree that is disproportionate to their length, compared to smaller than 35' bridge deck cabin cats. Exceptions exist, like my circumnavigator friends on the 34' Magic Carpet, but it's featherlite bridge deck cabin was less than 5' headroom. It was not a "family" boat. It was purpose built to offer maximum safety, over room.

WHAT JIM & JOHN EMPHASIZED IN DRAWING THEIR CATS:
Jim & John shoot for a much higher level of simplicity & seaworthiness, (even at the expense of accommodations), than the average production boat crowd. Because of this, they would need to be much longer in the WL than some, before they would put a full height bridge deck cabin on them. Then you are into a price range where most folks that can afford the one off professionally built boat, would be MUCH more comfortable with investing in a production boat, for it's superior accommodations, and less financial risk than a "one off", at least as far as the bank is concerned. These boats "not becoming common as cruisers" is true, but it's not because they wouldn't make good ones, it is for financial reasons, and because these days, the backyard builder is quite rare.

IF I wanted a "smallish" cruising cat, (by today's standards), and was considering a world cruise, I wouldn't be doing it with family for one thing. As a couple, however, I think a purpose built "cruising version" of the SR 40 Catamaran, with the low windage/light weight bridge deck cabin that they often have, would be "the cat's meow". IMO... Over a 10 year cruise, it would be less hassle to sail, own, and live on, than most of what's out there.

The design combines light weight, great performance, low COG, low windage, FULL visibility forward, easy walking space, and incredibly rugged construction, with world class wing clearance.

In their drawing amateur catamaran builder plans that strike the perfect balance between building simplicity, cost, boat speed, comfort, and seaworthiness, (just like with SR tris), I suspect that what they would do, is what they "did do".

For making money, on the other hand, John has designed some pretty incredible power cats that are like palaces. With custom designs, It is all a matter of what the customer wants. Now... let us stick to Trimarans:

"Re: Trimaran - Especially Searunner - Owners"

Mark

[Boatguy30]

Hey mark

I had a look at my SR 34 drawings, looks like my cabin top will be about 30" higher than the 34 roofline and only about 9' long. Keep in mind I am going with no more than 6' of headroom on my boat. Interesting perhaps how that compares in survival conditions with the wind age aloft of extra spreaders, stays, runners, etc, etc. Either boat would howpfully be on a sea anchor in those conditions anyway.

Anyway, enough of that. I was not aware of to many 34s that had done much serious voyaging. There is one in Auckland that was sailed from the west coast of US and a few that sailed to Hawaii. The trimaran thing was nearly over when the 34 came around it seems. It would be interesting to hear more about the Cape Horn one.

[blewett_john]

This a propeller question, which I posted in the propeller forum but I would like to get the Searunner owners' perspective:

I have a Searunner 37 trimaran with a Volvo Model 2003 28 hp diesel. There is currently a 19" x 11" solid 2-blade prop. I can get my hands on a 18" x 12" feathering 3-blade prop.

Is this a good swap?

Also, is a feathering prop left hand (LH) and right hand (RH), or is it either specifically LH or RH? The prop I am looking at is in a consignment shiop and is not marked well. It does not look like any of the the feathering props I have seen online. The pitch is not adjustable, the blades have tabs that hit stops. The blades rotate by the shaft turning an inner hub.

Thanks,

[Boatguy30]

Maybe post a pic of it. It will most likely be RH for forward. I suppose it might work in LH, but blades would be in reverse. I believe the max prop can be made LH by turning the blads 180 deg, but not 100% sure. Maybe you could turn the blades around on the one you're looking at.

It seems to me almost all sailboats use a RH so your situation is unique. I would call PYI and tell them you want to buy a max prop and see what they tell you about whether it is a special prop or just a different setup of the standard.

[Doggone]

Originally Posted by blewett_john

This a propeller question, which I posted in the propeller forum but I would like to get the Searunner owners' perspective:

I have a Searunner 37 trimaran with a Volvo Model 2003 28 hp diesel. There is currently a 19" x 11" solid 2-blade prop. I can get my hands on a 18" x 12" feathering 3-blade prop.

Is this a good swap?

Also, is a feathering prop left hand (LH) and right hand (RH), or is it either specifically LH or RH? The prop I am looking at is in a consignment shiop and is not marked well. It does not look like any of the the feathering props I have seen online. The pitch is not adjustable, the blades have tabs that hit stops. The blades rotate by the shaft turning an inner hub.

Thanks,

I have a Max feathering prop on my SR40 that has been great. The blades are the same RH or LH. For that reason reverse is very powerful. If your current prop is allowing full RPMs the size sounds close. Good luck.

[Mark Johnson]

REGARDING THE PROP QUESTION:
Hard to say if RH = LH of that particular prop, without knowing the brand. IF like MaxProp, the blades are symmetrical & flat, AND the degrees after being "stopped" are the same on flip OR flop, it will probably work either way.

What you want is a prop that will let your engine reach maximum "short duration" RPM, but just barely so. If you er just a bit on the side of... it's too easy to reach max RPM, that is OK. On the other hand, IF it can't reach Max RPM at all, and this is by a large margin, you will carbon up the engine in a big way. The notion that a larger prop is always "better", is a myth.

In achieving the best way to have the correct bight, (= JUST reaches Max RPM), larger diameter is better than more pitch, IF larger diameter still gives at least 2" of blade tip clearance to the hull. If it doesn't, then people often resort to 3 bladed VS 2, OR go to more pitch. This is the only reason to switch to a 3 bladed prop.

Prop size comparisons are not a matter of diameter, but of total blade sq inches. SO... If you compare a similar 2 bladed prop to the same size 3 bladed prop, (in T blade sq inches), the 2 bladed prop will be more efficient. It will push the boat better, on less fuel. This is because, the fewer blades means they are further apart, which results in it's running in less propwash from the blade in front of it. In theory, a SINGLE bladed prop is the most efficient, but that will not work, due to being impossible to balance.

SO... shoot for a 2 bladed prop IF it will fit. Your fixed prop gives you a starting point. IF it is just the right size, then I'd get that size & pitch in a folding prop. They are not as good in reverse, but have advantages... like being more slippery, more efficient in forward, and when folded, they don't snag crab pots!

MIT did a huge study for Practical Sailor, and found that the 2 bladed "geared" FlexOFold was most efficient in forward, AND most hydrodynamic when folded. This was compared to the same sized Martec, MaxProp 3 blade, Gori, Fixed 2 & 3 blade, etc.

I chose the FlexOFold for this reason, and still love it. The prices are WAY less than MaxProp, and you may get a dealer to swap out the blades on a FlexOFold, if you guessed wrong on the pitch, and only ran your new ones for 15 minutes or so...

That's definitely what I'd do... The thing about a consignment shop's "no-name" 3 bladed feathering prop, is that they not only have the disadvantages I mentioned, getting JUST the right amount of bight, is hard to accomplish right off. I would only consider it IF they would let you return it, if & when you find it is not quite right.

IF you really want or need a 3 bladed prop, I'd pay more for one with adjustable pitch, like a MaxProp. Then you can get it "just right".

Good luck,
Mark

[Roy M]

I like a folding prop, specifically the Martec Mark 3. The prop, for me, is an auxiliary device to the sails, and shouldn't create a marked interference in the primary function of sailing. In San Diego, we have extensive kelp beds that can catch any projecting prop blades, feathered or fixed. Only a folding prop sheds the strands immediately. Though the performance is not great in reverse, I'm not in that gear for more than a minute, at most. In forward gear, I can do hull speed at 2250 RPM with a Yanmar 3GM30, so I'm happy about the auxiliary power. When I'm done motoring, to achieve maximum performance, I rotate the shaft by hand to align the prop's blade axle to the vertical position so that forward sailing motion folds the props up tight.

[Cavalier MK2]

Originally Posted by Boatguy30

Not to expound on this much further.....

. Would like to hear more about the "Nano" tech paint. It makes me think of the "space age" TV infomercials. Very exciting!

The Behr exterior latex (I won't call it paint for peace reasons) uses Nano technology to adhere really well in adverse conditions and work without a primer. That said I think a coat of grey for UV protection followed by 2 top coats is a good idea.

We've had this stuff on for the last 5-6 years and it is still there. Right now we have the bangs, bumps and slimes of the rugged life but we haven't fussed on the exterior for the last couple years as we install the interior remodel/rebuild off the beach in warm weather. This means tracking mud, sand and grime over the boat on a daily basis and the paint is still there as well us undergoing the year round fire hose treatment at speed under sail.

We used regular exterior porch latex for the decks but it is more brittle and not as "sticky". Gulls drop shells confusing the decks for a land mass and it can cause chips so we will switch over. With latex hi traffic areas will wear quicker but it is ridiculously easy to touch up.

I like the softer look which tends to de-emphasize things like sanding marks etc.....but it isn't for the yacht shine people. Houses in all climates hold up year round with this latex. Just be safe with the boating crowd and don't call it paint! It is a eco sensitive, cost and labor saving alternative for those who have thick enough skin to survive becoming boatyard pariahs