They are actually pretty good swimmers.
Sloths are not known for being particularly speedy on the ground.
They get around on dry land by dragging themselves along the ground with their front claws.
But in the water all that changes.
BBC
Sometimes sloths fall directly from trees into rivers.
What with this and rainforest floods, swimming is a useful ability for sloths to have.
But their long arms mean paddling through the water is no problem at all.
BBC / youtube.com