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Talkin’ boats with Dave Gerr

Director of the Westlawn Institute of Marine Technology

Dave Gerr is the director of the Westlawn Institute of Marine Technology and a naval architect and yacht designer. He is known for the diversity of his work, and his designs include a 76-foot tunnel-drive aluminum motoryacht, a 60-foot ultralight racing sailboat and a 41-foot jetdrive express cruiser.
Gerr grew up in New York City, surrounded by boating books, and he built his first pleasure craft when he was 18 — a Phil Bolger-designed sharpie. A Westlawn graduate, Gerr, 58, started designing megayachts and commercial vessels at the age of 26 in 1979 at MacLear & Harris, a prestigious design office in New York.

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He established Gerr Marine Inc. in 1983 and has since produced dozens of recreational boat designs. In 2003, he was appointed director of Westlawn, a not-for-profit educational affiliate of the American Boat and Yacht Council in Eastport, Maine, that teaches yacht design. Gerr takes on one design project a year because of his Westlawn work.
He has written five books, including the well-known “Propeller Handbook” and “The Nature of Boats.” He lives with his wife, Barbara Curialle, in New York City and enjoys boating and composing classical music.
Here he talks about why he believes hybrid power for recreational boats makes no sense, names his most challenging design projects and explains why he generally prefers sailboats over powerboats.

Q: I read that you design boats to achieve success in these areas: beauty, seakindliness, strength and efficiency. Would you explain this?

A: Yes, seakindliness is a key. Too often today, boats are designed with only the consideration of top speed or maximizing accommodations or dock appeal. I want to see a boat that will take care of a crew, be comfortable, be safe, behave well at sea. It makes being out on the water that much safer, more fun and enjoyable. Strength goes back to the same issue. Boats are often built to cost. They’re to appeal at the boat show dock or for accommodations. A strong boat takes care of a crew, and you’ll feel safe. Here’s a story: One production builder was trying to sell a boat to a customer and they went offshore and got into a storm and came back. The customer tied it up with a single bow line and said, “It’s yours. I don’t want this.” He didn’t know much about boats, but he knew this boat wasn’t strong or safe. Efficiency means a powerboat gets good range for a gallon of fuel. For a sailboat, it moves fast, moves well for a given sail area. This is important for the cost of owning a boat also.

Q: Is there a vessel that would make a good example of all four characteristics merging well?

A: A couple of good examples might be Imagine, the Kanter 57 aluminum voyaging motor cruiser. Another one is the 41-foot Santa Cruz Coastal Flyer. It’s a beautiful jetboat that’s very fuel-efficient, very seakindly. I don’t think it’s our most beautiful boat that has come out of this design office, but a lot of people tell me that.

Q: When you talk about fuel efficiency, what kind of mileage — miles per gallon — is decent for a boat?

Gerr's jet-driven Coastal Flyer and aluminum-hulled Kanter 57 (pictured) combine good looks, seakindliness, strength and efficiency.

A: I can’t really give you a number because it varies from boat to boat. A big boat will have different mileage than a smaller boat. A high-speed boat will have different mileage than a displacement boat, and so on. What you are really looking for is how can you be as efficient as possible for a particular kind of design. There’s no mystery to it. Any designer worth his salt knows that if you want to make a more efficient boat, a longer, more slender boat is always more efficient. If it is properly proportioned, it’s also more seakindly. Also, a key is to operate the boat at a little slower proportion of its total hull speed. A boat should be sized in terms of displacement, so if you have a 30,000-pound 40-footer and you stretch it to a longer, more slender 30,000-pound 50-footer, the 50-footer will be markedly more efficient and get much better fuel economy. Let’s say these are semidisplacement boats. The 40-footer would be run at a speed-to-length ratio of 1.3 or 1.4 max. The longer boat could run at the same speed-to-length ratio, but would be going faster in knots.
A technical article about efficiency is in the Westlawn quarterly journal “The Masthead.” In part of it I talk about hybrid power. A lot of people talk about better efficiency and they think hybrids. Hybrids are not the answer for boats. They work very well for cars, but they do not for boats. They are a dead loss in almost every instance on a boat in spite of the hype, and it seems intuitively that it should be good.

Q: Why doesn’t hybrid power make a good fit for boats?

A: They’re useless in terms of efficiency. They can be really good for other things. I am not condemning them, but in terms of getting more efficiency, they’re pointless in a boat. There are many reasons. First, land vehicles generate savings when braking or coasting downhill. Boats never get that benefit — at all. Land vehicles spend a lot of time at idle speed or stopped in traffic. Boats don’t normally operate like this. There are some exceptions — trawlers, for instance. In those cases, a hybrid vehicle runs on electric power alone. Boats don’t get that opportunity at all. On an even more fundamental level, with any vehicle, any time you convert power from one form to another you have a loss, so in a boat where you have a diesel or gasoline engine that’s driving a generator, there is some loss in that [transition]. Then you charge up batteries, and there’s considerable loss in that. When you convert the energy from chemical energy to electrical energy there is some loss, and when you go back to mechanical energy and drive the motor itself there’s more loss. With a hybrid vehicle, the power created by the engine originally versus the power received at the propeller shaft is about 80 percent. That is the best you can do. On a standard direct-drive diesel installation or normal gasoline engine installation, 95 to 96 percent is the norm. The fundamentals are there, and they’re unavoidable. You can do things like add solar cells and/or run the boat more slowly, but the reality is you’ll always be paying a penalty. You’ll see claims for hybrids with impressive numbers, but if you look at it carefully you will see — they’re running the boat more slowly. So if you install a smaller, properly proportioned direct drive — diesel or gas engine — and run the boat at the same speed you will get more savings. Hybrid boats feel like they should work. People who manufacture them are well-intentioned, but on boats for efficiency almost always there is no gain, usually a dead loss.

Q: So there are other ways to be more efficient, such as building longer and narrower, as you mentioned. What are some other keys?

A: The propulsion package is important. For most boats that are not high-speed, the larger-diameter and slower-turning propeller is more efficient. So by simply going to a longer, slender hull with the same displacement and optimizing the propeller and drivetrain you can get a truly dramatic increase in efficiency. Unfortunately, this doesn’t have the sex appeal as the fancy, high-tech hybrid stuff does. There is another problem: Dockage is based on length and it should be based on displacement. So there is a series of things built in that mitigate an effort to go in the direction of a truly more efficient boat.

Q: What was the most challenging yacht for you to design?

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A: Part of the appeal of designing is the design process is challenging, and I enjoy that. If I had to pick one with my back to the wall, it might be the 60-foot BOC racer [Holger Danske] we did quite a few years ago because of the extreme light weight. It came out with a displacement/length ratio of 40, which as far as I know is still the lightest as-built and as-launched ocean racing sailboat, monohull or multihull. There was a tremendous amount of calculations — pages and pages of structural calculations, hydrostatic stability calculations.
Q: And which design stands out as being the most fun or enjoyable to work on?

A: Another difficult one to answer. Whatever I am working on is rewarding. The ones I enjoy the most are the ones I dream of owning myself. Boats like my tunnel-drive motor cruisers, like the 42-foot Summer Kyle and 47-foot Peregrine [both built by Covey Island Boatworks] I enjoyed slightly more than others because you say, “Boy, I would like to own that boat.”

Q: When you walk the docks of a boat show, what do you see that you like and what do you see that makes your stomach turn?

A: I tend to favor classic boats. It’s much harder to get a modern look that’s attractive. Most of the boats I see at a boat show don’t do much for me. Very high, bloated boats that are very white and smooth are very unattractive to me. There are some nice boats out there. One is Rodger Martin’s Presto design. By coincidence he’s a Westlawn grad. It’s a very sensible, efficient 30-foot sharpie. A totally different boat a few years ago was a big 120-foot motoryacht — I think it was a Palmer Johnson. It was a modern boat I thought was really beautiful. I like boats that embody the things I believe in — seakindliness, beauty, efficiency. I tend to lean toward classic [boats] certainly.”

Q: How and when did you get into the marine industry?

A: I am born and raised in New York City. I went to camps with boats. My father was always talking about boats. He had boat books around. We went sailing a lot with friends. We had a house in upstate New York in Johnstown. Boats were always around in my family. My father had been a ship’s carpenter. He’s smarter than me. He got out of the boating business and became an electrical engineer. But he was always around boats. My uncle ran away under square-rig sail in 1928, back when you could do something like that. My father’s original copy of “Skene’s Elements of Yacht Design” was on my desk when I was a kid. I was studying physics at NYU. I probably would have drifted through that, but NYU ‘s uptown campus was closing, and instead of moving to the downtown campus I reconsidered and transferred to Pratt Institute to study industrial design. Then I decided industrial design was not engineering-oriented enough, but physics didn’t provide enough of an avenue for design. And I discovered Westlawn, and I never looked back. For me, it was the perfect combination of art and science and engineering, and it has been close to 35 years and I just can’t get enough of it. I thoroughly enjoy it all the time.

Q: Do you own a personal boat?

A: Yes. I don’t get to use it much. It is a custom design of mine — Madrigal, a 20-foot canoe stern, all-varnished lapstrake sloop. Right now it is up in a yard in Connecticut. There’s an outboard bracket, but I hardly ever have the outboard out.

Q: What is your favorite personal boat and why?

Holger Danske, a 60-foot BOC racer, was designed to be extremely lightweight.

A: I couldn’t pick a favorite. The first boat was the one I built when I was 18 — a Phil Bolger-design sharpie that I built in my backyard in Riverdale in the Bronx. For a short time, we lived in the Bronx. It was a good learning experience. I bought an old Pennant sloop, which was built out in Queens by a guy who made them up as he went along. They were plank-on-frame, and no two boats were the same. We had a good time on that. I designed a sailing garvey called Pippen, which we still sell plans on a lot. I had that built for me in Albany. After that we had Knarr, which is a Dutch 30-foot sloop. I couldn’t really afford much of a boat at the time — she was falling apart.

Q: You sound like a sailboat guy.

A: Yes, I started out as a guy who hated powerboats. But I have turned around completely. As I have gotten older and slower I think, well, maybe my next boat will be a powerboat. I remember we did a 40-foot sailing cat, and I went out for an afternoon on Long Island Sound — fast, great boat, moderate breeze. We had a great time. But by the time you come back to the dock it feels like you’ve played a couple games of baseball — jumping around the deck, trimming sails, hoisting and furling them. A couple weeks later, we went cruising on the Chesapeake for almost a week on Belle Marie, the 42-foot Summer Kyle tunnel boat. You get up in the morning and go up to the pilothouse, press a button and up comes the anchor and off you go. I’ve come to like powerboat design, even though I have always liked sailboats and that was my first love. I remember we had another 52-foot ketch, Magic Moment. She was on the Hudson, not far from my office. I was out doing speed trials. I had the engine on a couple of hours, and then there was that “ah” moment — the sails go up, the engines go off — and you’re like, “Oh, my God, isn’t that nice.” So I don’t know. I’ve done more powerboats than sailboats by a wide margin, but I guess my preference would be sailboats.

Q: Who are the superstar graduates of Westlawn?

A: There are dozens: Tom Fexus, Bruce King, Jack Hargrave, Rodger Martin, David P. Martin, Bill Shaw, Rod Johnstone, Royal Lowell, Britton Chance. If you go to our website, there is a list of success stories (

Q: Who are some of the designers you admire?

A: L. Francis Herreshoff. I don’t refer to [his designs] anymore, but for a decade or so they were my models. His designs are just exquisite. Bill Garden is another one. William Atkin is the most prolific designer of small boats in history. He is fairly well-known, but I don’t think he gets the credit he deserves. Dick Newick — I love his multihulls, truly revolutionary designs.
An Italian designer — Renato Levi. His powerboat work was just exquisite. He was one of the premier racing powerboat designers back in the ’60s.

This article originally appeared in the August 2011 issue.