Marine VHF radios will perform much better when connected to their correct antenna. The antenna should be designed so that radiated waves travel in the required direction - there is no point directing radio waves up into space when all of your contacts are on or around sea-level!
A poor quality antenna will not provide the required good match & may provide you with questions about your installation and whether your radio equipment is working correctly. That is why we suggest you use a good quality antenna from a reliable manufacturer.
When purchasing a VHF antenna you should consider; Range, Gain, Mounting and connections.