Actor Julian Lewis Jones (Zero Dark Thirty, Invictus) was filming a fishing documentary in Australian waters when he noticed a struggling wallaby in the water. Interestingly, wallabies are competent swimmers and can move each leg independently while in the water–something they rarely do on land. While their speed is nothing to be impressed by, wallabies and kangaroos are relatively at ease in water and can swim for long periods. Some people have noticed that wallabies may swim from island to island in the search for more abundant food.
However, they are not meant to be ocean-faring and open water is definitely a dangerous place for the animal to be.