Sea Raycers are available for rent at the Wilderness Lodge. I have rented them there myself several times. Prices can change, but the rates during the summer of 2008 were $30.00 for 30 minutes, $40.00 for 45 minutes, and $45.00 for 60 minutes. My family generally rents the boat for an hour and my husband and I switch off as drivers (back at the dock) in the middle of our rental.
I think the Sea Raycers are one of the coolest way possible to explore the Magic Kingdom resorts area. These little boats can zip all over Bay Lake and the Seven Seas Lagoon. You can get a close-up, water-level view of the Wilderness Lodge, Fort Wilderness, the Contemporary, the Grand Floridian, the Polynesian, and, best of all, the Magic Kingdom.
Thank you, and best of luck to your son. I hope you all have a magical time together before his deployment.