Extending a 31' Prout front +6' ,rear+4'

Some opinions on speed if i extend a 31' prout by 6' bow,very sharp
reverse entry wave piercing bow. and added 4' to rear for steps/stairs. i intend to do in solid fiberglass.

 

I just finished such a project and it appears to be successfully meeting my original objectives. I did not appreciate the complexity of it. You’re talking about modifying the two most complex ends of the hull. There’s a reason why boats get lengthened by cutting them in half in the middle where the runs are parallel. The bow is complex but doable. If you get into having to modify the rudder...you just immensely increased the complexity.

Plan on doubling your budget and tripling your time estimate. I wouldn’t do it again knowing what I know now.

How would you do it in solid fiberglass? Do you have molds?

 

do you have a picture. the 4' at rear for sewage and water on other side. will be beyond the rudder.rudder stays as it is. The front will be sculpted to shape using styrofoam, then glassed to thickness and overlapped onto hull maybe 12" inside also glassed to hull.original bow remains inside intact.access port to view inside of front addition will be from top round hatch. for lightweight stuff.

 

styrofoam 2" panel for shaping. and glassing on top, BUT not directly to it, it will melt.

 

This would be significant increase in weight.
Most of catamarans after such extension would experience structural issues as the structure is not designed for such increased weight.

 

Not to mention the increased buoyancy?will see when actually done and used in 10' seas.

 

Here’s the bow extensions. They are aluminum