Related Clues:

• Man abstaining with support group around? There's competition for the water
• Inverted fraction of wattage rating which may involve eights
• Races a number of cars — volunteers to go head-to-head
• Event with boat races
• Craft meeting
• Head of regiment, say, attending army do at Henley
• Sponsor (eg, attaché) keeps this event afloat
• Boat race meeting
• Great at organised water-sports
• A target set out for meeting between banks
• The main event?
• Set a target for races at Henley
• Boat races
• Yachting gala
• Wet race-meeting