You could be running way too much power if

TrailBeast said
Like this?
Then you need a PL259 Coax connector.

RadioShack PL-259 Coaxial Connector (2-Pack)

And here's a video on how to install he solderless type.

View attachment 1714945923

Del beat me to it. :D

That there would work for HF (CB and lower freq) but that is NOT how it's done for VHF. Marine is VHF, up in the 155mhz range, and deserves 'correct' work.