I prefer to use duplex cable when installing gear. Just as important is the size of the speaker, and where you locate the radio. Inside a storage area, this reduces the chance of the wire getting pulled off or stressed. With any modern radio it only takes a moment to press some button that allows you to reset all the stations that are local and that you want to listern to. VHF is Line-of-Sight - which means that the distance will be limited by the curvature of the earth.
For reasons indicated above, many boats have a lot of background noise, and the operator may otherwise have difficulty hearing conversations.
Installing A VHF Radio
For the antenna connection, I prefer to use Shakespeare brand "CenterPin" solderless connectors rather than the connector that typically comes with the antenna. You'll also need to bring the antenna cable up through the hole — which will probably mean cutting off the old connector. The 'continuous power supply' is to ensure the radio keeps its memory of channel settings when the other supply is off. I think I probably just join the yellow and red together but someone once told me that wiring up a car stereo the wrong way can instantly destroy the thing so I think I'll wait a day or so and see what advice I get. This not only allows you to layout where to make the cut, the blue tape protects the underlying surface from scratching. Scanning is a process whereby each receive channel is scanned in sequence, not unlike a "police" scanner.