Uniden - VHF Marine 2-Way Radio - Multicolor

It depends on a number of factors. Weather is one, sea state, obstructions between you and the person you are calling. Generally, you can get out 3 to 4 miles and still hear the other person. We've see as far as 7 miles away. With marine band, it's a good rule to use 'line of site' when determining if they can copy you or not. Some radios have a low/high switch which allows you to go from 1 Watt of power to 5 watts of power. People think that if they stay on hi power all the time, it will help the signal. Again, not true. If you are in a wooded area along the shore, that can also have an effect on your transmission capability. And of course, battery life. If your batteries are running low, that will affect your ability to reach out. Also, transmission on high all the time weakens the batteries quicker so be sure to check your settings.

Yes, this unit has a headset jack.