If you're looking to win summer, this right here is 100,000% how you do it: the Seabreacher is a semi-submersible personal submarine that 1) LOOKS LIKE A BADASS SHARK, 2) goes 50mph above water/25mph under it, and 3) LOOKS LIKE A BADASS SHARK SERIOUSLY GUYS ARE YOU SEEING THIS????
Fifteen years in the making, the bionic shark is manufactured in Redding, CA and weighs just 1,300+ pounds, meaning it can use a 260hp engine to literally whale-breech itself out of the water.
As for the "submarine" part of the equation, it's less "dive! dive! dive!" and more "it can go under the water for short stretches," but honestly who cares. You're driving a freaking shark. Or a killer whale with a blowhole. Or a dolphin. Or a shark with an octopus on it. Or a sailfish. Because, whambamthankyouunclesam it's available in the shapes of all of those animals, too.
Oh you want dope standard features? They've got those: there's a snorkel-mounted video camera, an iPod-compatible stereo system, LCD screens, and the ability to make literally anyone at the lake immediately pee themselves when you roll up on them.