Copyright 2014 CONRAD YACHTS All Rights Reserved
Hull Characteristics.
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(20 degrees), makes her much more comfortable
in sea way than the majority of boats this size, whose deadrise is generally in the 13 to
18 degrees range.
3. The innovative, variable width chine flats are wide aft, gradually narrowing , from
amidships 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 it from
slamming against oncoming chop.
4. The hull itself is 28 feet long, 30 feet including the swim platform(optional).
5.  The Tuna 28 IB hull is specifically designed for a mid engine; for those who
prefer a direct drive installation, and an unobstructed aft end of the boat. It is a bit
deeper forward to accommodate a  Centre of Gravity located closer to the centre of
the hull.
Tuna 28 IB - #14
Centre Console
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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 9'.
3. Whenever possible, welds are avoided.
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(s), if necessary, even after the boat is completed. This is
accomplished by locating the fuel tanks under a “soft patches” 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
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1.  The Tuna 28IB hull can be equipped with a propeller "pocket" for  less draft, or it can be used as an unmodified
2. Custom alterations will be considered (additional and/or different configuration of lockers or seating).
3. Built into the cockpit sole, on centre, can be a  fish hold, with a flush lid, built-in drain and a removable liner.
4. It is possible to make the boat unsinkable(not required legally at this size), by filling the unused cavities under
cockpit sole and in the sides, with foam.
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Assembly Drawings:                          
( for
detailed construction study only )
Digital Package:                                             
  1. Assembly drawings.
  2. Parts list.
  3. Nest.
  4. The use of the cutting files-CNC cutting.     
please enquire
Building kit:                                                         
  1. All plate parts, cut and formed.
  2. Assembly drawings.
* Does not include tubing, cleats etc.
** Pending current price check at time of purchase
please enquire
  • Hull length
28 feet
  • LOA
28 feet
  • Beam
9 feet
  • Draft - hull only
20 inches
  • Draft - propeller
(pocket drive)
28 inches
  • Deadrise at transom
20 degrees
  • Minimum cockpit depth - no rail
29 inches
  • Fuel capacity
120 USG
  • Power - single inboard diesel
150-500 hp
  • Capacity ( people)
  • Metal weight
4,000 lb
  • Design displacement
7,400 lb
Other Features.