The answer is probably Venusaur. It looks like a tropical island, so we can assume a tropical climate and tropical pokemon. Venusaur would do well against most types except flying, but you have to take an L. Venusaur is low maintenance, provides shelter, and can help with food growing if you find berries or some sort of coconut. Plus, vines can be used to build nets which can be used to fish.
>>57523980Boiling ocean water is useless. It is still toxic and will kill you if ingested in large quantities.