These are nice. couldn't find an exact match but I believe they are key fobs (chains)
So I looked on the web and ebay at keychains, fobs and found lots of potentially useful little things, some other nice little boat fenders, life jackets
steering wheels, etc. I am a scratch builder but this could an easy inexpensive part source for some things.
I also have a proboat Volere
which I like a lot. When I first got it, it ran O.K. but pushed up a big bow wave. First thing I tried was moving the battery
from the middle of the boat to the back, I cut off the unnecessary parts of the servo horn and then I could put the battery
easily into the stern. I bought a additional battery
of the same type on ebay for a few dollars except 9.6V instead of 8.4V. That helped a lot too.
Having success I changed the motor, still brushed to an 05 size for an airplane. (master airscrew ma 3560)
Now she easily rises right up on plane and goes like a speed boat should.