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The 43' Aluminum Trawler Yacht


Boojum 43 - A Trawler Yacht by Kasten Marine Design, Inc.
Larger Aft View | Side View | Portside Forward

General Concept

This 43' power vessel has essentially the same mission statement as the Greatheart 48: "Fit the maximum boat into the readily available robust 4 cylinder marine diesel engines." The Boojum 43 prototype shown here is intended to share the same interior layout (exactly) as the Greatheart 48, since it has the same waterline length, and the same displacement. Still, they have different hull forms as follows...

The 43 foot Boojum has a hull form similar to the Boojum 25 and the Buster 30. However, the Boojum 43 shown above has lines that are a bit more fine, very much like the Terrier 32 and the Nidaros 38. In each of these designs the fantail stern and plumb bow contain the overall length very nicely. As a result the Boojum 43 is about 5 feet shorter in overall length than the Greatheart 48 even though both vessels have the same displacement, the same waterline length, and the same interior.

Particulars of the Boojum 43 model shown above are: 43 feet length on deck, 40 feet WL light, and 41 feet WL loaded. Displacement will be around 30k lb. light and around 40k lb. loaded. Beam is 12.5 feet.


Sails are a possibility for use as emergency get-home power. A conservative ketch rig has been sketched. The Greatheart 48 has twin keels of a modest size. The Boojum 43 shown above also has twin keels shown, but they are not a requirement. The twin keels would however allow sitting on the mud upright. They would also carry a small quantity of ballast for enhanced roll attenuation, and for the sake of providing windward performance under sail as a get-home strategy.

Power required will be around 80 to 85 hp for the Greatheart 48, as well as for the Boojum 43. Engine choices are the 4 cylinder John Deere, the 4 cylinder Lugger, the 4 cylinder Cat 3304-B or any other small four cylinder marine diesel in a similar power rating. The JD or Lugger provide a bit of weight savings over the CAT engine even though they provide the same horsepower. Top speed will be around 8.5 knots. Range is anticipated to be over 3,000 NM using around 700 gallons of fuel.


As shown for the Greatheart 48, the Boojum 43 layout will have a cabin for children or guests located aft, having two quarter berths and a big school desk or bureau on center aft. In the Pilot House will be a settee sized to seat four comfortably. Forward, the galley will be on both sides below the companionway. There will be a pair of easy chairs forward of the galley to port and starb'd, essentially forming the ship's library and galley social area rolled into one. Forward of that will be a head to port, and a shower / tub to starb'd. The forward stateroom is for the owners, and features an island berth right forward with very adequate hanging lockers and other storage.


An alternate layout and slightly heavier displacement hull form are shown below - a prototype that I've called the Borgnes 43. The difference is that the Pilot House has been shortened just a bit, making room for a large settee below and forward. The galley in this case would be located to one side, with the settee / dinette opposite. This arrangement also allows a slightly larger head / shower forward.

See below for a view of the layout, and for rendered images of this version...

Boojum 43 - Kasten Marine Design, Inc.
Click for Larger Image

You will notice several key differences on the Borgnes 43. With this hull there is more displacement in order to accommodate an all steel structure. As a result, among the commonly available 4 cylinder marine diesel engines, a turbo would be specified. Also, there no bilge keels planned, and the cabin structures are slightly different. In this case there is a cabin trunk for the forward accommodations, allowing the exterior decks to all be at one level. As is evident in these images the pilot house is slightly shorter, which allows enough space below for the larger saloon and galley area. In all other respects, the Borgnes 43 layout is the same as that of the Boojum 43.

Boojum 43 - A Trawler Yacht by Kasten Marine Design, Inc.
Larger View Above Aft | Portside Forward | Aft View Low | Side View Aft

For yet another variation, please see the Far Horizon 43 prototype, which has very much the same hull form and cabin arrangements, but with a bow that is shaped more like that of the Greatheart 48. The result is a slightly shorter WL length, therefore slightly less displacement and a little bit less space below.

Design Summary

As compared to the Greatheart 48, the Boojum 43 and the Borgnes 43 are considerably more "stout" looking, while the Greatheart 48 is much more "sleek" looking. These prototypes provide an example of the hull form variations that can be achieved using the same interior, as well as variations on the interior theme - on the one hand to have a settee in the pilot house, and on the other to have a generous dinette below.

Either way, the result is very fine indeed...

Similar Designs and Prototypes in this Tug / Trawler Yacht Series

Tug Types
Boojum 22 | Boojum 25 | Boojum 30
Terrier 32 | Talisker 32 | Nidaros 38

Trawler Types
Sweet Okole 30 | Buster 30 | Boojum 43
Roberta 43 | Roberta Jean 43 | Roberta Jean 47
Far Horizon 40 | Far Horizon 43 | Far Horizon 46 | Far Horizon 50 | Far Horizon 54