Wild ponies made their yearly swim to Chincoteague from Assateague Island, Maryland, Wednesday in front of tens of thousands of onlookers.

The ponies started the swim shortly after noon today. It was one of the latest swim times in years. The ponies make the swim at slack tide — the time between the tide change when the water is perfectly still.

They crossed a 200-yard channel to Chincoteague, where they will then be auctioned starting tomorrow to raise money for the volunteer fire department, which cares for the ponies.

Ponies that are not sold and those that are donated back to the fire department will roam free for another year on the national wildlife refuge on Assateague.

The pony swim was made famous by Marguerite Henry's 1947 novel "Misty of Chincoteague."