I have used this antenna as a mast head antenna (50 and 63 feet above the water), also on a radar arch 12 feet above the water. I also used it with a 3 foot SS base extension on the C Dory 22, because of the fact that the fiberglass 8 foot antennas, come back into the cockpit when laid down, and are subject to being broken.
However, there is just no sense of using this antenna on a Tom Cat. The Tom Cat lends itself perfectly to two 8 foot "Digital" 529 or 829 (brand) antennas, with gain of 6 dB. SWR depends on antenna design--and the Digital 529 is a far superior design, as well as considerably more gain. Again--something not to go"Cheap" on. You can break any antenna--of course the SS whips are certainly harder to break. But again, that should not be an issue with the Tom Cat.
Also check on the threads about the virtues of having two VHF radios.
Be Safe!