CB SWR meter is not accurate at marine bands frequencies 155 MHZ vs 27 MHZ for CB they usually good for up to 30 MHZ. Buy a good quality UHF/VHF coax, CB/ham HF coax has line loss at VHF frequencies, I use mil-spec silver-Teflon pl-259/n connectors on all my ham/marine radio's. High SWR conditions radios have self protection to save the final TX transistors will cut back power by over 90% . Ask a ham operator to help with a SWR meter if you do not have the correct meter, if you do not know one look here
www.qrz.com/db/?cmd=1
type you zip code and a list of local hams will come up we are more than happy to help.