Lower Rhine
Cygnus olor
The swan is a legendary bird, which could be why we don’t eat them. The Schwanenburg (Swan Castle) in Kleve got its name from the legend of a knight in shining armor saving a damsel in distress, and arriving in a boat drawn by a swan.
I don't know about pulling a boat with a man in it, but the bird is fairly powerful. Once while out doing photography in an early morning I stumbled upon a pair with a very young chick. The male reared up and hissed at me. He gave the impression that, not only could he pull a boat, he could also inflict some serious discomfort on a photographer. I wasn’t worth his trouble, thankfully, and he let it go with just the hissing. The bird is especially beautiful in flight, but too content to loll around for one to see that very often.