You’re Stranded on a Desert Island (not dessert)

(1) Water Purifier - gotta have it to live until you can use Flare Gun.
(2) Matches - gotta have it for fire until you can use Flare Gun.
(3) Tent - gotta have it to stay dry (and to keep the matches dry) until Flare Gun.
(4) Flare Gun to GTFO, or at least to hope of GTFO.