While Alcids and Penguins flap below sea level, that's technically swimming

While down at North Beach the other day, the lowest flying birds were Barn Swallows, largely. In fact it would be about physically impossible for a bird to fly lower - they were only about an inch off the sand.

What they were after were the many tens of thousands of "beach flies'"
feeding on washed up seaweed and whatnot. It was fun to watch which I did for quite a while, tired and sitting on a log.

Jeff Gibson
Log Sitting in
Port Townsend, WA