The prize is the thing. For young swimmers, for a prize, they will go to the end of the earth.
It is all it is; just a simple tangible award. Almost any prize will do. It can come in almost any shape or size. The exclusivity of the reward gives it it’s worth and the coach can decide that (or the parent). Pickle Rick did fine.

Pickle Rick, if you don’t know, is an animated character in a tv programme. Space travel, time travel, multiple universes. That kind of thing. My teen boys enjoy that show and in one season Pickle Rick keeps showing up in the episodes.
In a gift shop there was a large pillow size Pickle Rick. Of course everyone wanted it so my Wife said whoever wins a gold medal tonight can get a Pickle Rick.
From that moment on it was the chat. ‘I’m getting Pickle Rick…no I am…’ etc. …and how did the night’s races go? From our three boys in finals; two got silver and one gold. We bought him the Pickle Rick.
Another great prize was when my group of swimmers stayed in a university dorm. At many universities there is a large rock in the middle of a communal green space. Uni students paint on it, graffiti it, and sometimes even use it to communicate events; party at Randell Halls flr 4!
For that competition the group was strong and we would have a good three or four swimmers medalling and also relays each day. So each night we went out and anyone who won a medal got to put their name on the rock. It turned out to be one of my best ideas for prize giving motivation ever!

Mr Potato Head was a close second or third place in the good prize category. I would peruse a charity shop (second hand store) and found, in great condition, in-the-box, Mr Potato Head. I gave that to the biggest improvement in a finals for the entire meet. (I did think long and hard about keeping it for my own collectibles). I showed the swim group at our first competition day, pre-finals meeting, and everyone wanted it. How did it go; let’s just say ‘outside smoke’ became a regular occurrence! I even got inspired to draw a pencil drawing later on;

I even stoop to the level of candy. I have a warm up called ‘snakes & ladders’ which is an easy fun warm up. The winner (or winning lane) gets a sweetie (that’s a candy for north american folks). The sweetie prize never fails to get swimmers in early and meaningful prizes rarely fail to improve performance.
I do draw the line at cash for PB’s. I think that cash does work but it takes a bit of the magic away from a prize. Cash is not a prize but rather a payment for a job. But that’s just me.