Complex sentence: Staines Amateur Regatta was established in 1850 one year before Staines Boat Club, and whilst they are two different organisations, SBC members now act as volunteers in running the regatta.
Split into simpler sentences: Staines Amateur Regatta was established in 1850 one year before Staines Boat Club. Whilst the regatta and boat club are two different organisations, Staines Boat Club members now act as volunteers in running the regatta.