It seems that turtles and on occasion chickens, get stuck in boats moored at the edge of the water. This has happened for as long as I can remember, possibly even when I was testing 1.13. It seems that no matter what I do, it will randomly occur. 

 At first I thought it somewhat amusing, but it has happened so long that it's now problematic and became more so with the recent bug that placed one outside their bed or structure walls while sleeping (thank you for fixing that). Anyway, I expect there to be no stuck turtles and chickens in the boats. Please examine the images, some from different snapshots, etc.