The UIM F1H2O World Championship is the premier single-seater inshore circuit powerboat racing series. Sanctioned by the Union Internationale Motonautique and promoted by H2O Racing, it has run continuously since 1981 and is broadcast in 170 countries. This is the definitive guide to the series.

What Is the F1H2O World Championship?

F1H2O is the highest level of circuit powerboat racing in the world. The boats are single-seater, closed-cockpit, twin-sponson tunnel-hull catamarans. They weigh 550 kg including the driver, produce around 400 horsepower from a 6-cylinder outboard engine, and accelerate from 0 to 100 km/h in approximately three seconds. Racing takes place on rivers, lakes, harbours and sheltered bays on circuits roughly 2 km in length.

The championship was conceived in 1978 by promoter David Parkinson with support from Mercury Marine and inaugurated in 1981. H2O Racing has promoted the series since the mid-1980s, with Nicolo di San Germano leading the organisation since 1993. The championship did not run in 1987, 1988 or 1989, nor in 2020. It has been sanctioned by the UIM throughout its existence.

For the 2026 season guide, entry list and timetables, see: UIM F1H2O World Championship 2026: Everything You Need to Know.

Boat and Engine Specifications

The boats are built from carbon fibre, Kevlar, Airex and Nomex composite materials. Minimum dimensions are 5.10 m in length and 2.1 m in width. The carbon fuel tank holds approximately 120 litres of 100LL Avgas.

The primary engine is a Mercury 6-cylinder outboard. The 2-stroke variant (Mercury 360 APEX) produces approximately 400 hp at 10,000 rpm. A 4-stroke option producing around 360 hp at 7,000 rpm is also homologated. Drive is direct to a variable-pitch stainless-steel propeller via a fixed-ratio gearbox, with hydraulic controls for engine trim and height. Boat manufacturers include BABA, Blaze, DAC, GTR, Molgaard, Moore and Victory.

Safety equipment includes an energy-absorbent composite cockpit capsule, HANS device, airbag system, 9 mm polycarbonate screen, 5-point harness, life-support air supply and deformable frontal crash structures. The canopy is latched closed for racing. These standards have contributed to a dramatic reduction in serious incidents since the enclosed cockpit era began.

Race Format

Each Grand Prix weekend runs over three days. Day one covers free practice and the drivers’ briefing. Day two runs a three-tier qualifying session to set the grid, followed by two 15-minute Sprint races with the field split into groups. Day three brings a second free practice session, a parade lap, the 30-minute Grand Prix, and the podium ceremony.

Starts use a pontoon grid, with boats held by crew members until the start signal. Drivers experience up to 4.5G in cornering and braking. Water conditions vary significantly between venues.

Points Scoring System

Additional points are awarded for pole position. A separate Team Championship runs alongside the Drivers’ Championship. The Sprint race format and current points system were introduced in 2024.

2026 Season Calendar

2026 Teams and Drivers

All-Time World Champions