This is a large inflatable canoe (I think it would be dangerous to use it on the sea). Depending on the size of the people using, it would easily fit 3. It's been in my family for a VERY long time, but the plastic it's made of (vinyl, I think) doesn't seem to deteriorate at all and is easily reparable with the right glue and patch.

I haven't blown it up for many years, but it's been nicely stored away so I think it's well worth trying if you fancy it! I don't have paddles for it, but I think those are easy to find.

Inflatable canoe (Hastings TN34)