I'm no expert, and have just visual estimates from probably 40 trips by each shore. Also I'm not sure what you mean by "right off". But I'll give it a go. On the south, depths seem to stay under 10 out at least 100yds., although there are some "holes. About half or 2/3s of the way to long key there is a deeper channel of ? depth. On the east, the beach runs out probably 30-80', then there's a slight channel(with bonefish). The north end appears deeper, but I doubt you can find 20' anywhere all the way to Caye Caulker. The west side again seems to be similar, although some dredging took place to accomodate their harbor. Still I've gone pretty much WNW a mile ot two and never DIDN'T see the bottom. Hope this helps.