Sam, that is *really* interesting. Now that you say it I can well imagine that the great fat "foot" of the Scheel keel would create quite a bit of suction when embedded in nice sticky mud. Gack!
PSC 37 Kenlanu with Scheel Keel
We have a Scheel keel and it works well. But I would not get another. The fin's a few inches deeper but points better - and that does make a difference when you're covering miles. Most of all when (not if) you run aground it offers a much smaller footprint to get out of the mud or sand (or rock or coral if you're really unlucky).
s/v Grace PSC34#163