: I have been thinking about building a normal bow instead that long
: bifid one for example... or/and reducing (-5%) the lenght
: between the cross sections.

Reducing the distance between frames will work and is exceedingly easy. Don't make the cockpit smaller, unless you want a smaller one . . . .

Or this, of course -
: Otherwise I should change the boat and build something wider (the
: sea tour 15 exp maybe ?).

Good luck!
Dave