Possible configuration for a GA28????

[Trevor L]

I am interested in the GA28 as a cruising boat for extended trips.  I have read through many of the forums and I am really impressed by the creativity of the many modifications and Brians support in steering builders in the right direction.  I have attached a picture of a layout that I would like to accomplish if possible.
After spending 8 months on a 37ft sailboat, we have a good idea of what we are looking for, so curious if the GA28 would be the right boat.  I have changed the arrangement in the pilothouse which includes extending the rear bulkhead over 20 1/2 feet from the bow, which is quite far past Brians aft limit of 218", but I thought with an extension of the transom to a floating bracket/swim platform might help if the aft limit is due to a C of G calculation or is it a structural issue? anyhow I thought it would be worth asking if this configuration is feasible/recommended. 

[Rbob]

I like the arrangement, well thought out for your intended use.  Brian will chime in on the structural stuff.

Nice to see new ideas.

[Brian.Dixon]

Looks like it'll work fine as drawn!  The aft house bulkhead location is more flexible than the aft cuddy bulkhead, in terms of exactly where it's place ... 218" is about 18' ... your 20-1/2' location is fine but probably as far aft as I'd go.  More importantly, is that if your 3 tanks are filled, the center of gravity will be in approximately the right spot.  As you use up water and fuel, it'll change of course - something to keep in mind (try to use furthest-aft fuel tank in balance with water usage more or less, a tad stern heavy is better since the boat will self-bail that way).  And you're right - the longer version of the boat is more forgiving of all of the above.  Finally, I can't quite tell from the top view, but I assume your swim step/transom extension is what I suggest ... just extending the full-width hull further back and putting a swim step on it.  Suggested extension for a 28' hull should be not more than 24".  Since you're running fairly heavy, this is fine.

Brian