This reminds me of the story about Tom Hank's, stuck on the deserted island, and he has one box that he won't open. Zemeckis, the director, jokingly said in an interview that the box contained a waterproof, solar powered, GPS enabled satellite phone.
But if Gilligan had a satellite phone, I'm sure he'd screw it up and drop it in the fire or something.
The most important thing the SS Minnow was missing was a weapon to kill Gilligan. All they ever had to do was get rid of him and they would have been rescued 1,000 times over. But I'm not bringing up anything new - entire books have been written about killing Gilligan and the metaphor it represents.