I went out to the dinghy. The fuel tank was bloated as I had closed the air vent on the fuel tank. I opened it, let the excess air out and tried to start the engine. After about 50 pulls I decided the engine was flooded. (I was both relieved and distressed when two cruisers were also unable to start their engines.) I returned to shore for about 15 minutes. When I returned I once again tried to start the engine again. No luck. Then I remembered from the carburetor days of my youth! I cranked the throttle fully open and pulled. A cough. Pulled a second time - zoom zoom! The magic solution from my youth.
Fair winds and following seas :)