The distance your radio will work effectively to communicate with another is called its range, and that's a very important factor to consider when choosing a VHF radio, whether a handheld or boat-mounted model. If you want to communicate with other boats several miles away, you're going to need look for a very strong radio that can accommodate your wish to communicate with someone at that distance. Since boat-mounted radios have separate antennas, they typically have a longer range. If, on the other hand, you only need to communicate with family members at a campsite a mile or two away, a radio with much shorter range will suit your needs just fine. When shopping, try to get an idea of a radio's effective range before making a purchase.