Just my $0.02, but you don't want your party spoiled by worrying about your draft when the tide is out and a monster powerboat goes by. Anchor in deep enough water that you don't have to worry and row in. If you question the depth, then it's too shallow.
I once spent 2 days with a broken exhaust elbow tied to a dock at Gwynn's Island off the Piankatank River. Each low tide, we'd hit a hard sand bottom every time that a powerboat went by which was often. It's a wonder that there was no damage. You don't want that kind of worry; it spoiled two days in which we could have been pleasantly stranded in Gwynn's.
Sabre 38 "Victoria"