If you want a bargain-priced sea scooter from a name-brand manufacturer, the Yamaha Explorer is hard to beat. It's designed for kids and doesn't quite support the speed and depth of some of Yamaha's other low-end (as opposed to professional) scooters, but it should be fine for family water outings and has a camera mount so that your younger family members can keep a record to show their eventual grandchildren how exciting things were back here in the early 21st Century, before the coral reefs became completely bleached and the ocean life died off from climate change. (Those eventual grandchildren will no doubt complain that the Explorer didn't record holographic images with an interactive time-travel option, but they'll still be amazed that grandpa and grandma got to see what the oceans were like before they completely took over half the coastal land masses.)
The Yamaha Explorer can take your junior scuba diver to depths up to 30 feet and speeds up to 2.5 miles per hour, or just pull them along on a leisurely snorkeling trip through the local bay. (You don't want to use it if the only water you're likely to visit is a freshwater lake, because it requires salt water for bouyancy and your youngster will sink to the bottom of a freshwater pond, requiring mom and dad to make a quick dive to rescue them, or the Explorer, from the murky depths.) Should the youthful driver lose his or her grip, the unit will pause and wait for them to catch up. The lead-acid battery in the unit is good for an hour of cruising and the entire unit weighs 11-1/2 pounds, so mom might want to lend a hand helping her brood carry their equipment down to the dock.
Yamaha considers this an entry-level unit, so if you're already into the world of sea scooting, you might want to give it a pass for a more advanced model, but you still might want it as a holiday present for your budding aquatic offspring. If you're shopping for yourself, you might look at the Suex Xjoy 37, the Torpedo 2000 or the deep-diving Submerge Scooters Magnus.
An entry level model designed for younger recreational divers and snorkelers.
Cruising at speeds up to 2.5mph (4km/h) with a depth rating of 30ft (10m) the Explorer is perfect for shallow dives, snorkeling adventures or chasing fish.