Hello, I don’t know much about the series (like how many there are) but it appears they were only minted 1974-1975.

There are a lot of cool ones, but like you said way too expensive through eBay. In researching I found so many that would be nice to have! 😄

Speaking of silver vessels there is one on eBay that has a cute little fishing ship. 2 of the same bar one is $27 one is $97. Condition, condition, condition. ☺️