How are kangaroos very strong swimmers?

Kangaroos are not very strong swimmers. They can swim, but they are not particularly good at it. They are marsupials, which means that they have pouches that they carry their young in. When a kangaroo is swimming, the water can get into the pouch and weigh it down, making it difficult for the kangaroo to stay afloat. Kangaroos also have large, heavy feet that can make it difficult for them to swim effectively.