Great Design Trawler Truths Design Discussions Economy Our Naval Architect
Truth 1 Truth 2 Truth 3 Truth 4 Truth 5 Truth 6 Truth 7
Truth 1 Truth 2 Truth 3 Truth 4 Truth 5 Truth 6 Truth 7
TRUTH NO. 3: A SAILBOAT HULL IS NOT A GOOD TRAWLER HULL
Sailboat hulls are great for sailboats, period! Sails and the tall rig make a sailboat stable, but not only does a trawler with a sailboat hull have deeper draft, but it will wallow in one-foot seas. That's why some builders push expensive stabilizer systems, which are practically guaranteed to fail when needed most. Instead, we at Great Harbour Trawlers had naval architect Lou Codega to design an inherently stable, true displacement hull.
For the most informed discussion of hull design, we've asked Lou Codega, to explain why sailboat type hulls - with their deep draft keel and round bilges - are NOT the ideal design for trawlers. Here's his answer:
:I continually read of builders and colleagues touting what they perceive to be the optimum hull for all conditions, having exactly the right blend of this quality and that aspect and this pedigree to make their hull the best choice for everyone under all conditions. That's frankly a bunch of hogwash and does you, our customers, a great disservice. The life of today's trawler yacht is just too varied to make one hull form the best for everyone at all times. In fact, no other aspect of naval architecture requires so much compromise as does the design of the hull itself, and the optimum hull just doesn't exist. The obvious solution is to anticipate how potential owners are going to enjoy their boats, and to design the best hull form for that spectrum of uses.
We have anticipated our owners living aboard for extended periods, even permanently and often independently in remote areas, with the comfort of a shore-side condo. Typically the boat will be crewed by two, exploring coastal areas or making annual migrations along the waterway. Offshore trips will be possible when the urge strikes under conditions that are as controlled as can be expected, by which I mean that forecasts for the passage will keep the boat out of true storms.
Because cost is also an important consideration, not only in the purchase price but also in maintenance and operation, we think we've designed a boat that does an admirable job of fulfilling the above goals. If your desires match with our emphasis, then perhaps we've made a good match.
The Great Harbour hull feels right at home almost anywhere, derived as it was from modern workboat hulls, not sailboats. I think that this is appropriate because a workboat has to earn its keep and keep its crew safe 365 days a year. The boat is not light, and design displacement is nearly as high as any boat of comparable length to carry the anticipated weights. But we chose to take the volume afforded by the high displacement outward, rather than down. This increases the usefulness of the accommodation space tremendously, allows for outstanding machinery access, and provides for cavernous storage spaces below deck. And the corresponding shoal draft opens up cruising grounds and anchorages that are inaccessible to her deeper draft sisters, to say nothing of removing much anxiety from waterway passages and inlet transits.
The hull has been shaped for continual economic operation at hull speed. You'll see little of the squatting and none of the large increases in fuel consumption that occur when boats with ship-like hulls are pushed as hard. We've selected a twin engine machinery layout as it is an ideal match with the shallow draft hull, allowing as it does optimum propeller diameters to keep blades above the bottom of the hull, outstanding maneuverability and built in redundancy. Test results on the Great Harbour 37 show that only 46 horsepower are required at hull speed. This is less than the rated power of one engine, and we can nearly reach hull speed on one engine, dragging a fixed propeller.
And we think that we've done well on the economic side, also. The boat is miserly in its consumption of fuel, and the generous tankage gives a lot of flexibility in choosing refueling sites. The same beam that gives you access for easy maintenance also allows her to be efficiently built. And it allows for fitting the desired accommodation into a shorter overall length, which will reduce dockage and maintenance expenses with very little penalty in performance.
:I continually read of builders and colleagues touting what they perceive to be the optimum hull for all conditions, having exactly the right blend of this quality and that aspect and this pedigree to make their hull the best choice for everyone under all conditions. That's frankly a bunch of hogwash and does you, our customers, a great disservice. The life of today's trawler yacht is just too varied to make one hull form the best for everyone at all times. In fact, no other aspect of naval architecture requires so much compromise as does the design of the hull itself, and the optimum hull just doesn't exist. The obvious solution is to anticipate how potential owners are going to enjoy their boats, and to design the best hull form for that spectrum of uses.
We have anticipated our owners living aboard for extended periods, even permanently and often independently in remote areas, with the comfort of a shore-side condo. Typically the boat will be crewed by two, exploring coastal areas or making annual migrations along the waterway. Offshore trips will be possible when the urge strikes under conditions that are as controlled as can be expected, by which I mean that forecasts for the passage will keep the boat out of true storms.
Because cost is also an important consideration, not only in the purchase price but also in maintenance and operation, we think we've designed a boat that does an admirable job of fulfilling the above goals. If your desires match with our emphasis, then perhaps we've made a good match.
The Great Harbour hull feels right at home almost anywhere, derived as it was from modern workboat hulls, not sailboats. I think that this is appropriate because a workboat has to earn its keep and keep its crew safe 365 days a year. The boat is not light, and design displacement is nearly as high as any boat of comparable length to carry the anticipated weights. But we chose to take the volume afforded by the high displacement outward, rather than down. This increases the usefulness of the accommodation space tremendously, allows for outstanding machinery access, and provides for cavernous storage spaces below deck. And the corresponding shoal draft opens up cruising grounds and anchorages that are inaccessible to her deeper draft sisters, to say nothing of removing much anxiety from waterway passages and inlet transits.
The hull has been shaped for continual economic operation at hull speed. You'll see little of the squatting and none of the large increases in fuel consumption that occur when boats with ship-like hulls are pushed as hard. We've selected a twin engine machinery layout as it is an ideal match with the shallow draft hull, allowing as it does optimum propeller diameters to keep blades above the bottom of the hull, outstanding maneuverability and built in redundancy. Test results on the Great Harbour 37 show that only 46 horsepower are required at hull speed. This is less than the rated power of one engine, and we can nearly reach hull speed on one engine, dragging a fixed propeller.
And we think that we've done well on the economic side, also. The boat is miserly in its consumption of fuel, and the generous tankage gives a lot of flexibility in choosing refueling sites. The same beam that gives you access for easy maintenance also allows her to be efficiently built. And it allows for fitting the desired accommodation into a shorter overall length, which will reduce dockage and maintenance expenses with very little penalty in performance.
