There is a reason why I tend to sail yachts rather than dinghies..... to avoid this sort of thing.
When its gusty on the Thames there can be rather a lot of swimming and my memories of getting the Laser upright and me inside involved a lot of bruises. Maybe that was why the sailor swam to shore for a recovery there.
A safety boat was around somewhere but nearer was the Thames lifeboat that happened to be passing by:
Also heading to shore (on another day) was the police boat, showing its flexibility and ability to get close enough to put the old bill on the Thames's muddy banks and then reverse off safely:
And here is one of the police boats in a more iconic location, down past Westminster Bridge with Big Ben in the background:
There you go.
Boats! Boats! Boats! on both Lake Geneva and the Thames.