Thanks all, the ideas are really appreciated.
Ashley, if I understand you correctly, some kind of wooden plate standing off from the stern. That might be possible without spoiling the look of the boat. I'll get me pencils out and see what it would look like.
Ray, I think that the two boats are so different that Vospers solution wouldn't work elegantly
Colin, the sailing only solution is a possibility, I'll give it some thought.
If anyone has a light bulb moment, please let me know, I'm still several weeks from building that bit.
Chas.