| Copyright 2008 CONRAD YACHTS All Rights Reserved |
Hull Characteristics.
1. The hull can be best described as a modified constant deadrise form, the most trusted and
well behaved hullform ever developed.
2. Relatively high deadrise at transom(18 degrees), makes her much more comfortable in sea
way than the majority of boats this size, whose deadrise is generally in the 13 to 16 degrees
range.
3. The innovative, variable width chine flats are 10” wide aft, gradually narrowing to 4”
amidships , to 2" forward. The wide chine flats aft give the hull extra lateral stability, while narrow
chine flats forward, allowing the hull to move through the water, prevent slamming against
oncoming chop.
4. The hull itself is 18 feet long, 20 feet including the engine bracket/swim platform. Including
the outboard engine, the boat is just under 22 feet long.
1. The hull can be best described as a modified constant deadrise form, the most trusted and
well behaved hullform ever developed.
2. Relatively high deadrise at transom(18 degrees), makes her much more comfortable in sea
way than the majority of boats this size, whose deadrise is generally in the 13 to 16 degrees
range.
3. The innovative, variable width chine flats are 10” wide aft, gradually narrowing to 4”
amidships , to 2" forward. The wide chine flats aft give the hull extra lateral stability, while narrow
chine flats forward, allowing the hull to move through the water, prevent slamming against
oncoming chop.
4. The hull itself is 18 feet long, 20 feet including the engine bracket/swim platform. Including
the outboard engine, the boat is just under 22 feet long.
| Tuna 18 CC 20' LOA |
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Specifications.
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Construction.
1. All major hull structure components are designed and calculated to conform to the requirements of ABS(American Bureau of
Shipping).
2. The maximum beam is 8’-0". This is relatively wide for a 20' boat. Tuna 20 is a stable fishing or working platform.
3. Whenever possible, welds are avoided: entire cockpit sole(from the bow to the engine bracket) is made of only two lengthwise
halves, welded together, then welded to topsides(side plates) around the perimeter, and slot welded to structural members
underneath. Each hull half is one piece, so are side plates. This approach yields a much fairer hull.
4. The hull is framed longitudinally, which, again, produces a fairer hull, eliminating the "hungry horse" look of many metal boats.
5. The structure consists of longitudinal girders and transverse frames, which “egg crate” into one another to make assembly
quick and accurate.
6. I believe in being able to access and remove the fuel tank, if necessary, even after the boat is completed. This is accomplished
by locating the fuel tank under a “soft patch” in the cockpit sole.
7. Alloys used are all top marine grade 5000 series.
Bottom - 1/4" - 5086 H116
Sides - 3/16" - 5086 H116
Cabin - 1/8" - 5052 H32
1. All major hull structure components are designed and calculated to conform to the requirements of ABS(American Bureau of
Shipping).
2. The maximum beam is 8’-0". This is relatively wide for a 20' boat. Tuna 20 is a stable fishing or working platform.
3. Whenever possible, welds are avoided: entire cockpit sole(from the bow to the engine bracket) is made of only two lengthwise
halves, welded together, then welded to topsides(side plates) around the perimeter, and slot welded to structural members
underneath. Each hull half is one piece, so are side plates. This approach yields a much fairer hull.
4. The hull is framed longitudinally, which, again, produces a fairer hull, eliminating the "hungry horse" look of many metal boats.
5. The structure consists of longitudinal girders and transverse frames, which “egg crate” into one another to make assembly
quick and accurate.
6. I believe in being able to access and remove the fuel tank, if necessary, even after the boat is completed. This is accomplished
by locating the fuel tank under a “soft patch” in the cockpit sole.
7. Alloys used are all top marine grade 5000 series.
Bottom - 1/4" - 5086 H116
Sides - 3/16" - 5086 H116
Cabin - 1/8" - 5052 H32
1. Transom height is 25”. Using the engine bracket, instead of mounting the engine(s) on the transom, allows the engine(s) to sit
a bit higher and further aft of the end of the hull. This improves the "hole shot" and allows the propeller to work in less turbulent
water flow. It is possible to use 20" leg motor, if preferred.
2. Recommended power for this hull is from 50 hp to 150 hp, single or twin installation.
3. Custom alterations will be considered (additional and/or different configuration of lockers or seating).
4. Cockpit is self-bailing.
5. The steering console is fitted with integral windshield and roof.
6. Filling the cavities under the cockpit sole with foam will make the boat unsinkable. This safety feature is required for boats
under 20' in length.
7. The windshield can be ordered as aft or forward sloping.
a bit higher and further aft of the end of the hull. This improves the "hole shot" and allows the propeller to work in less turbulent
water flow. It is possible to use 20" leg motor, if preferred.
2. Recommended power for this hull is from 50 hp to 150 hp, single or twin installation.
3. Custom alterations will be considered (additional and/or different configuration of lockers or seating).
4. Cockpit is self-bailing.
5. The steering console is fitted with integral windshield and roof.
6. Filling the cavities under the cockpit sole with foam will make the boat unsinkable. This safety feature is required for boats
under 20' in length.
7. The windshield can be ordered as aft or forward sloping.
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Pricing
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Model specific materials, for this version will be
posted as they become available.
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