Legend - I suspect that you may have a problem with the antenna connector. The 'ground' part of your antenna system is the metal woven shield of the coaxial cable and this must not make contact with the gold center pin of the connector. Screw-on (solderless) connectors are notoriously poor at maintaining good solid connections and you really require a waterproof solder-on connector.
If things are/were working properly, you should be hearing a lot of activity on the radio, especially on CH 16. Vancouver Harbour and Vancouver Coast Guard Radio are very strong throughout the lower mainland. Even Victoria Coast Guard Radio is loud over here.
You should be able to hear these signals, although weaker, even with a thin ~ 18" wire pushed carefully into the center pin of the radio's antenna socket. You might try this, just to conform that the radio is working and that you probably do have an antenna problem.
The condition that you are describing sounds like some of the shield wires may be touching the center-pin on your connector, thus short-circuiting your antenna system. You may want to carefully remove the connector and check that the shield wires are not all messed up or frayed looking. Even just one single loose piece of shield wire, floating around inside the connector can cause the short.
The other thing you should confirm is that your antenna model is for VHF Marine and not for 27MHz CB, as this will also cause the same condition as you describe.
As far as 'matching' the antenna goes.... if it is indeed a VHF Marine Band antenna, it is most likely already properly tuned. Even mistuned, 'received' signals will still be strong...the matching is more critical to transmitting than receiving.
Let me know how you make out .
Steve / VE7SL