Though rarely used after the series pilot, Jonas Grumby was the name of the Skipper on Gilligan’s Island.
You are not related to the Skipper; he is a fictional character from a TV show. But, if you are hard-pressed to fill out the real names on some of the branches of your family tree, in addition to regular weekday hours, the Richardson-Sloane Special Collections Center is open on the second Sunday of January, February, and March from 1-4pm for genealogy and local history research. Who knows? You might just find you have an ancestor in common with Alan Hale Jr. (the actor who portrayed the Skipper.)