Nine teams of people are competing against each other to pull a 14-tonne, 11-and-a-half metre lifeboat, a quarter-of-a-mile, in the quickest time possible.
It is all to raise as much money as possible for the RNLI.
The lifeboat will sit on a low loader during the event, creating a massive 37 tonnes for the teams to pull through the London park.
More top news
The mother of a former altar boy who tried to blow up a train insisted he was 'a big softie' who didn't want to hurt anyone.
Its current five year licence comes to an end next Tuesday.
Extra armed police will guard major sporting events in London this weekend after the military was drafted in to protect key locations.