Boat setup
Inboard
A boat with the engine mounted inside the hull and the propeller exiting under the hull forward of the transom, making it safe for wakesurfing because the rider stays away from the prop.
An inboard boat has its engine and drive unit placed inside the hull, with the propeller coming out under the hull in front of the transom. This is what makes inboards safe for wakesurfing: hitting the propeller is unlikely because it would require reaching well forward and several feet under the boat from the riding position.
Inboard wake boats are also purpose-built with deeper hulls that provide more water displacement to generate a strong wave. V-drive inboards, forward-drive inboards, and jet boats all keep the prop away from the rider and are appropriate for wakesurfing, whereas conventional sterndrives are not.