Your Favorite Hull Designs for Monohull Sailboats

[Don C L]

Pretty hard to beat this one too, IMHumbleO: "Stormy Weather" by Olin Stephens:
http://classicyachtinfo.com/yachts/stormy-weather/

[double u]

such a beauty - but uncomfortable & expensive for the amount of boat she is

[daysgoneby]

LUFFE 48

https://www.luffe.com/en-luffe-48-gallery

[mitiempo]

Here are some pics of the Luffe 48

[mitiempo]

Here are 3 more

[Steadman Uhlich]

I had not seen a Luffe 48 before. It looks nice. Sure has a very fine entry or forward quarter.

[Steadman Uhlich]

Sundeer 56 or 60 or 64

Steady's Notes:
I recently had the opportunity to board a Sundeer 56/60 while I was on another boat that had to raft up to it in St. John's (Newfoundland) harbor. While I was not able to see below decks because the owner/crew was not aboard at the time, I was very impressed by what I saw when I carefully and quietly crossed their decks to first tie up to the boat and then later, to get ashore.

The first impression was "high quality." Everything on this particular boat looked "Bristol condition" and all of the hardware and finish looked perfect. Everything from the teak trim (minimal) to the stainless was in perfect condition.

My second impression was of the hard dodger/Pilothouse. I liked what I saw. Some Sundeer boats have a soft dodger, but most apparently have a hard dodger (doghouse) or pilothouse. This one was long enough for two internal settees that looked about 6 feet long. It was very nicely constructed, and appears to give excellent visibility to anyone sitting inside on watch. On this particular boat, the doghouse/pilothouse had an enclosed build, with doors to the rest of the cockpit. I mention this, because I have seen others that were open (no doors enclosing the aft end of pilothouse). I very much liked what I saw. I suppose the doors could be removed in the tropics (on other boats), but in the cold water location I was in at the time, the thought of a nice dry and warm protected pilothouse/doghouse was appreciated.

My third impression was of the wide side decks as I walked forward towards the bow (we had to raft up). These boats are designed as flush deck boats, so the deck forward of the pilothouse is relatively flat and open. I walked forward and past the numerous large Dorade vents (the boat has 10), each with a granny bar guard around it. The impression I had was of "great working deck space" and "security" from numerous handholds and a higher lifeline (I estimate 32 inches). The relatively flat deck was covered in nice anti-slip paint. Everything felt "high quality" and well designed. There were several large square deck hatches too.

Here are some more facts and statements from my notes on this boat design. It is one of my favorites, so over the years I have collected some facts and snippets of descriptions. I encourage sailors to read about these boats and their design because they represent such a high level of "blue water boat design" and have many interesting features.

The photos I am posting below are simply added to illustrate this boat. The Sundeer line includes a 64 footer, and you may see one in the following photos, I am adding it to show the design too. They are very similar. The 56/60 is essentially the same boat, with the 60 having a larger lazzerette locker in the stern.
______________________

Some Facts and Opinions by Reviewers:

Steady: Designed by Steve Dashew. To learn more about Dashew, google his name to find his site "Set Sail" and then read his bio and some of his books (he has provided several of his excellent books as free download PDF files). I learned a lot by reading his "Offshore Cruising Encyclopedia" 28 years ago, and it is one of his free books today. Highly recommended.

Snippets from other reviews:

"They were built by Tillotson Pearson Industrial Composites or TPI for short in Warren, Rhode Island.

They produced seventeen of the 56/60 Sundeers from 1994 to 1997.

They regularly average over 200 nautical miles a day offshore.

The Sundeer has large capacity tanks carrying 400 gallons of water and 220 gallons of fuel.

Steady: By design, there is no requirement or need to have a watermaker or generator, or in most places an air conditioner.

A good review (written in 2000) tells some details.
A New Dawn for Sundeer - boats.com
Here are some excerpts:

"All raw water intake is via a single through-hull fitting that feeds a manifold with taps to the engine, fridge, toilets, etc., and all output is through a single exhaust above the waterline in the stern of the boat, or through big structural standpipes that require no seacocks. Each of the segregated watertight compartments in the boat has its own electric bilge pumps, and a single high-capacity engine-driven crash pump has intakes plumbed into each compartment for emergency use.

With a Displacement/Length ratio of 80, the boat's hull qualifies it as an ultralight racer, but its rig, with a Sail Area/Displacement ratio of 17.5 is, by comparison, quite conservative. This is the core of the Sundeer concept: a light, very easily-driven hull coupled with a modest, easily handled sail plan.

Most importantly, the radical D/L is achieved not through radical lightweight construction, but primarily through hullform. This is not a large boat, but a long one that maximizes waterline, arguably the single most significant factor when it comes to performance, while minimizing beam, thus greatly reducing wetted surface while maintaining directional stability. The entry is very fine and the bilges are rounded rather than flat, reducing both horizontal and vertical wave resistance. Because the long, narrow hull has good directional stability and does not need a tall rig to drive it, the keel can be kept short and shallow, further reducing wetted surface while enhancing structural integrity. For cruising sailors this has added benefits. The six-foot draft allows access to shoal-water cruising grounds, and the 64-foot mast can squeak under bridges on the Intracoastal Waterway.

Steering and Sail Handling: What struck us most about the Sundeer is that under sail she does not feel at all like a 60-foot boat. From behind the wheel, the impression is of an easily managed 45-footer. Only when one starts moving forward along the deck toward the bow and notices the trip takes longer than expected is the boat's true size made apparent.

In anything approaching favorable conditions, it will be easy to push this boat over 200 miles a day, and in ideal conditions, you should see around 240 miles.

But the most remarkable aspect of the boat's speed is how effortless it can seem. On several occasions in moderate conditions, when it felt as though the boat was just lazing along, we glanced at the speedo and were surprised to find we were turning a crisp 10 knots.

One may be tempted to dismiss the concept of a 60-foot boat that can be easily sailed by one or two people as oxymoronic, but, in fact, it is not. Again, this is not a large boat, simply a long one. The rig is short and the sails can be set, reefed and furled without any electric or hydraulic assistance. The deck and interior are very comfortable and easy to move around in a seaway. The systems are well thought out, easy to access and maintain, and can, if one chooses, be kept extremely simple for a boat this size. "
__________________

Specifications for the Sundeer 60

LOA 59'11"
LWL. 59'0"
Beam 13'6"
Draft. 6'0"
Displ. 36,500 lbs.
Ballast 11,500 lbs.
Sail area 1,205 sq. ft.
D/L 80
SA/D 17.5
B/D 32%
Engine 88-h.p. Yanmar 4-cyl. diesel
Fuel 220 gals.
Water 400 gals.
Designer Steve Dashew
Builder TPI Composites, Inc. & Sundeer Yachts

[daysgoneby]

Beam, Drag, Steering, and Rig Size

Seeing Moonshadow ensconced between two broad beamed production yachts got us to thinking. She is a few feet longer than either of her neighbors, significantly less beamy, with a rig one quarter or more shorter. Which configuration do you suppose is quicker, or would you rather sail short-handed across the ocean?
Take a look at the photo of the rigs. Moonshadow looks like we forgot to add the upper mast panel.

We don’t want to get ahead of the ARC crossing results, but when you compare her times to the rest of the cruising yachts, and think of her rig, you are going to be puzzled.

The answer is simple. Herewith are the basics of cruising yacht efficiency. To begin with, beam equals drag and has a negative impact on steering. For a given performance level, the fatter the boat the taller the rig. As the rig goes up so does the vertical center of gravity, so you need to add lead and draft to the keel.

The taller rig looks cool, but at best, can only offset the extra drag that come with beam. Can you handle these bigger sails efficiently, short handed? Probably not.

The beamier boat, with its larger and heavier rig, extra rigging, and hull surface, area weighs more for the same factors of safety. So it requires a larger engine, which is… heavier and take more fuel (lots more in fact). The bigger engine and its larger tanks for a constant range eat up interior volume. Of course there is a larger diameter prop shaft, the strut has to be longer and beefier, and the prop is bigger.

All of which leads to yet a bigger rig. You can see the design spiral here.

So why have a fat boat in the first place? Good question. The boats laying alongside Moonshadow are probably three feet wider. What do you get in return for the drag? If the interior is kept simple, you will have more visual space. But if you fill this with extra lockers – which always happens – the visual space remains the same as Moonshadow’s 14.5′ beam. And she has those four feet of extra length in which to put interior or storage.

As drag goes down with reduced beam less rig is required (which makes for a more easily handled vessel), draft can be reduced, and the boat steers more easily. And in a breeze you are going to be quicker.

What drives designs in this fashion are charter needs and owners who want lots of guest accommodations. The beam, carried aft, creates two large aft cabins. We have no argument with this concept, if that is what you want. But if you are cruising as a couple, with occasional guests, you are paying a very high price for those cabins which are being used mainly for storage.

Want proof it works this way? Watch the daily runs and the differences between Moonshadow and her beamy neighbors.

SetSail FPB » Blog Archive » Beam, Drag, Steering, and Rig Size

[Brob2]

Originally Posted by daysgoneby

Beam, Drag, Steering, and Rig Size

Seeing Moonshadow ensconced between two broad beamed production yachts got us to thinking. She is a few feet longer than either of her neighbors, significantly less beamy, with a rig one quarter or more shorter. Which configuration do you suppose is quicker, or would you rather sail short-handed across the ocean?
Take a look at the photo of the rigs. Moonshadow looks like we forgot to add the upper mast panel.

We don’t want to get ahead of the ARC crossing results, but when you compare her times to the rest of the cruising yachts, and think of her rig, you are going to be puzzled.

The answer is simple. Herewith are the basics of cruising yacht efficiency. To begin with, beam equals drag and has a negative impact on steering. For a given performance level, the fatter the boat the taller the rig. As the rig goes up so does the vertical center of gravity, so you need to add lead and draft to the keel.

The taller rig looks cool, but at best, can only offset the extra drag that come with beam. Can you handle these bigger sails efficiently, short handed? Probably not.

The beamier boat, with its larger and heavier rig, extra rigging, and hull surface, area weighs more for the same factors of safety. So it requires a larger engine, which is… heavier and take more fuel (lots more in fact). The bigger engine and its larger tanks for a constant range eat up interior volume. Of course there is a larger diameter prop shaft, the strut has to be longer and beefier, and the prop is bigger.

All of which leads to yet a bigger rig. You can see the design spiral here.

So why have a fat boat in the first place? Good question. The boats laying alongside Moonshadow are probably three feet wider. What do you get in return for the drag? If the interior is kept simple, you will have more visual space. But if you fill this with extra lockers – which always happens – the visual space remains the same as Moonshadow’s 14.5′ beam. And she has those four feet of extra length in which to put interior or storage.

As drag goes down with reduced beam less rig is required (which makes for a more easily handled vessel), draft can be reduced, and the boat steers more easily. And in a breeze you are going to be quicker.

What drives designs in this fashion are charter needs and owners who want lots of guest accommodations. The beam, carried aft, creates two large aft cabins. We have no argument with this concept, if that is what you want. But if you are cruising as a couple, with occasional guests, you are paying a very high price for those cabins which are being used mainly for storage.

Want proof it works this way? Watch the daily runs and the differences between Moonshadow and her beamy neighbors.

SetSail FPB » Blog Archive » Beam, Drag, Steering, and Rig Size

It seems clear to me that it's the type of sailing that drives hull shape for racers. Obviously, as you say, many cruisers and charterers expect cabin space and fat boats can provide that, but the shapes of Comanche and Wild Oates were almost solely drawn for boat speed, yet they vary notably. One excels as the wind moves forward, the other as it moves back, just as the designers intended. One is a fat boat, the other is not. When they face each other apparent wind direction and velocity usually dictate the winner. Vendee Globe designs are fattys as well, and interior accommodation has nothing to do with their shape.

Translated to cruising boats the principles still generally hold, with the noteworthy issue of weighty equipment onboard.

[daysgoneby]

Originally Posted by Brob2

It seems clear to me that it's the type of sailing that drives hull shape for racers. Obviously, as you say, many cruisers and charterers expect cabin space and fat boats can provide that, but the shapes of Comanche and Wild Oates were almost solely drawn for boat speed, yet they vary notably. One excels as the wind moves forward, the other as it moves back, just as the designers intended. One is a fat boat, the other is not. When they face each other apparent wind direction and velocity usually dictate the winner. Vendee Globe designs are fattys as well, and interior accommodation has nothing to do with their shape.

Translated to cruising boats the principles still generally hold, with the noteworthy issue of weighty equipment onboard.

The extreme shapes of the Open 60s are driven by their rule. The stability aspects drive the search for power. Take out that and the 60′ LOA and the Open 60s would be longer, narrower with smaller rigs.