Hi Mark, if you are going to go to the effort of replacing the antenna you need to consider that the coax could be shot as well. Once water gets inside the inner elements of the coax it can corrode things significantly and could be the root cause of any issues you have as generally the antenna just is a fixed length of wire in simple terms. I’ve had a scenario on one of my boats where the corrosion in the coax went all the way back to the plug that goes in the back of the transceiver.
You will only ever ‘really need’ your VHF radio when you really need the radio, best not to compromise on the kit or the quality of the installation.