Whether or not you need a waterproof cooler depends on what you are using to cool it. If you are using one of the best ice packs for coolers, then it’s not essential because the amount of condensation that will come off your perishables and ice packs is negligible. However, if you plan to use ice cubes to cool your small cooler then it becomes more important. During testing I found that non-waterproof coolers tended to tip and spill quite easily. I would recommend purchasing a waterproof cooler if you plan to use ice as your primary cooling mechanism.