Summary: What could be the last pleasure boat to depart downtown Petaluma left very carefully the other afternoon. Exactly 5 feet of water was beneath the hull of the Sea Witch as it inched away from the dock for a 20-minute voyage nearly as treacherous as the rounding of Cape Horn. “There’s a big bump of mud over there,” said captain Bob Boynton, his hand firmly on the tiller. “And another big bump of mud over there.
