The professor makes a dye marker to help get rescued. The Skipper plans to join the Navy when they get home, but he finds out he must lose weight to meet their requirements--and Gilligan finds out that he must gain weight too.
Did You Know?
At one point, Skipper is using nails to build the signal tower. In "Goodbye, Island", it was established that they had none. See more
Skipper Jonas Grumby
There's a table in this Navy manual that tells me how much I should weigh.
Maybe it's under "tonnage".