Hi Dave, my mk1 solution for a removable transom mount is here;
Fish finder on a 3.9m inflatiblr
in the rubber duck section.
It looks like I won't be alone bobbing about off Redcar in the summer, as there's a growing band of sibbers round here, Blond Chris, GJW and several others.
We'll have to get our acts together to out fish the yakkeres.