Where the East River meets the Long Island Sound is called Hell Gate. We timed our passage through there as our waterway guide had suggested and hit it right, but you could see by the disruptions on the surface of the water that it could be tricky.
The repairman diagnosed a bad lift pump and ordered one overnighted, and installed it the next day. Prior to the repairman's return, Joe sheepishly discovered a small roll of tape he had left on the engine had partially blocked the air intake to the engine. He removed it and the engine ran fine. the repairman discounted any cause other than the lift pump Joe wisely didn't argue ... so a new one was installed under warranty.