I bought a set of these Star Wars spaceship dive sticks on ebay today. The space ship pack comes with Poe Dameron’s black X-Wing, a New Order Tie Fighter and the Millennium Falcon.
The sticks are weighted and are about six to eight inches long and the ships themselves aren’t much bigger than a Micro Machines Falcon. I suppose you throw them in the pool and try to get them before they sink to the bottom.