Bonus boats are accessible by entering a combination to access the boat. Medium boats are in the middle, and Hard boats are usually very difficult to control but are very fast. The easy boats tend to be easy to control but they do not have the speed of other classes. The boats in Hydro Thunder are divided into 4 categories: easy, medium, hard and bonus.
This places the player "in the game" and makes the person feel like he or she is actually piloting a powerful, high-tech speedboat.
The game also has an unusual volume adjustment, where the regular play volume is usually set lower than the feedback volume for the subwoofer in the seat. The arcade version of Hydro Thunder utilizes the same basic cabinet as Cruis'n USA and Offroad Thunder, minus the standard foot pedals and adding a variable position throttle with forward, neutral and reverse directions. When combined with the many ramps on the tracks, players can reach short cuts and boost icons that would normally not be accessible otherwise. When the Hydro Jump is performed the player's boat is propelled into the air. Another aspect of boosting is the Hydro Jump which is performed by braking and using the boost button. Also by boosting a player can knock other boats into the air, a feature described by the game as the Mighty Hull. When a player has boost fuel they may use the boost button to boost, which allows a player's boat to reach speeds much higher than what would normally be possible. Red boost icons are more scarce than blue boost icons due to the fact red boost icons give more boost fuel. When touched these icons allow the player who touched them to boost. Scattered across the tracks are blue and red boost icons. The gameplay of Hydro Thunder consists of racing high-tech speedboats through treacherous environments, from the cold seas of the Arctic Circle, to a post-apocalyptic, flooded version of New York City.