Whats the most succesfull design for open water  for medium/ heavy weights!

A crash diet, perhaps??

We want to build one in the winter ,so if yer can ,constructive please.

Are you talking new or second hand?

I think he said build how do you build a second hand yot?

Both and you can take a mould off existing or build from scratch.

start with a new one a and sail it.

I thought thats what you do ? build a boat and sail it .

Open water as in the sea or a lake not closed due to foot and mouth or a hose pipe ban?

on the briny open sea,the bigger the better.

You may consider a Steppenwolf