Yes, yorkies can swim.

Cooper goes swimming, but he gets wet and then he likes to relax on a raft for the most part.

He likes to play with his toys in the shallow part. At first he wasn't sure if he liked it so I held him in the water and my husband would call him and eventually he swam to him.

I don't let him in the pool by himself. Someone responsible has to be there at all times(just like a kid)

I think the life jackets are for boat rides, but I could be wrong.