The Yak Attack Clave is a totally awesome idea... one suggestion would be to hold it on Brewster Flats. I think Don Baker (Sesuit Creek Outfitters) might sponsor it there and offer a few varieties for us to try - no promises but I will ask him.
There is a sequence of flats and shoals that can be fished using yaks that I know quite well (or at least did before the winter).
There are sizable fish in spring and fall, I got a 38"-ish bass in 3 feet of water last fall and several keepers (released) in spring on foot. Two seasons ago I landed three over 30" in 7 casts, but it'll never happen again I'm sure.
The yak would only improve the odds as the fish clearly set up on different locations on different days. By mid-season they are off shore on Billingsgate Shoals 2 miles out - a bit far for yakkin' I'd say.
Another option would be Hardings Beach or Morris Island, sortie to the edge of North Monomoy's famous Common Flats. I'd pick a light Southeast wind to aid the return voyage(?)