Answer:
Sea water is infested with a lot of bacteria, there are 2 ways u can possibly drink it without getting sick
1. boil it. this will take away all the germs and bacteria
2. filter it. you can use a filtering water bottle or a life straw (if you don't know what a life straw is, see the link below.)
Note: The above answer is incorrect. While boiling (or pasteurization in general) does kill off most germs and bacteria and filtration does remove most bacteria, each is a necessary but insufficient process to create potability. Boiling the water alone will not remove the salt content which still makes the sea water non-potable. The same is true with filtration. In order to remove the salt, the water must be boiled and the steam collected in a condenser. The steam is re-liquified by cooling it in another container. The original container will still hold all of the salt, which is removed.