What should I put in my dry bag? It sometimes depends on what you do and the size of your dry bag. There are different sizes of dry bags that are suitable for different things. If you have a 5L dry bag it’s good to put mobile, keys, and a change of cloth for summer. But if the dry bag is 10L it can hold a few cloths and a pair of sleepers. For 20L dry bag it can also hold sleeping bag. If you want to dive it’s better to take 40L or even large dry bag as it can be used to put your wetsuits. But if you just want to take sunshine shower at beach you can take 5L or 10L dry bag as they are enough for a change of cloth and sun block.