Passenger boats are accelerated along a submerged guide rail structure that is arranged in various closed loop courses, including “Figure-Eight,” hour-glass, serpentine and oval patterns, as well as linear guide track structures that extend in parallel between a launch station and a return station. A dual “Figure-Eight” watercourse includes a simulated jump ramp and an under-ground tunnel arrangement. The launching and operating speed of each boat relative to the other is controlled so that the boats approach and pass in close proximity to each other and then recede from each other as they travel in opposite directions along adjacent guide track sections, and in passing, project water spray onto each other.