GBS when we get together on the crab pot we can talk antennas. It really does depend on which model you have - yes transmitting without an antenna connected to the radio or an antenna that doesn't match the output of the radio (within reason) is a bad thing. However, depending on which antenna you have will govern whether the antenna will still work. For instance - Shakespeare Galaxy antennas use a sold brass or silver plated brass pipe to form their antenna elements - while they do have a piece of wire that goes further up the antenna it is usually constructed from the center conductor of marine coax - glad to show you the inerds of my Digital Antenna I broke.
If you have a lower end Shakespear like the 5206, the entire antenna element is made from flexible coax instead of pipe and uses a small matching stub to balance the antenna.
One more time the white fiberglass is not an electrical component of the antenna it is merely a radom that is transparent to the antenna - or simply a support/weather resistant structure.
Maybe we should just meet at where you boat is, I'll drag my SWR meter along and we can check it - do not let it get wet inside that radom - wet coax stays that way.
In the grad scheme of things - if it was my life depending on that antenna I would replace it and not risk it - antennas are cheap. If you do replace it Shakespeare Galaxy series or Digital Antenna 500 Series - yes more money, but they are better antennas (unless you mistreat one like I did :grin
Edited to be easier to read