Nick,
My combined log/sounder is mounted on the bulkhead, port side, as standard. It protrudes inwards through the inner moulding, which is cut out around it. It doesn't catch on sheets or halyards.
Quite a lot has been said on this forum about swivelling brackets, which might also be worth considering. Some good photos have been posted. A swivelling bracket mounted on the inside of the bulkhead allows a display to be viewed from below or from the cockpit, and it can be tucked out of the way when not in use. I haven't got one, though, so I can't vouch for the idea personally.
Anthony Russell
235/02 Sea Wyche
Anthony Russell
235/02 Sea Wyche