Complex sentence: Thames skiffs were developed in the 19th century for leisure use by private individuals sculling themselves, being based on the Thames wherries and shallops that were operated by watermen as a water taxi service in London.
Split into simpler sentences: Thames skiffs were developed in the 19th century primarily for leisure use by private individuals sculling themselves. The design was based on the Thames wherries and shallops that were operated by watermen as a water taxi service in London.