Bill,<br><br>Marine radio and HAM 2m band are both VHF frequencies. The HAM band is between 144-148MHz and the Marine band is between 155-162mHz. The Marine radios are "channelized" into frequency pairs that are preset and allocated to specific uses. Channel 16 and 22 are US Coast Guard channels. Marine operators are required to monitor Channel 16 so this can be a great advantage if you can contact boats or ships. Gain as much elevation as you can, and attempt to Call on Channel 16. Most Marine radios come with a very short antenna, try and buy a longer higher gain antenna if possible. <br><br>VHF radios are line-of-site radios and their range is determined by both the power output and antenna gain. Handheld 2m HAM radios generally operate at between 0.5-7watts output, and their practical range is a few miles. Most operators in this band use repeater systems that have elevation and high gain antenna to receive your signal, then rebroadcast it at much higher power to a wide range. In Seattle, it is easy to hit repeaters from backcountry mountaintops from 30+ miles at 5Watts output, then have your signal rebroadcast for ~100+ miles from an unlinked repeater, and hundreds of miles in a linked repeater system. <br><br>Handheld Marine Radios operate at essentially the same frequency and have the same limitations. You generally do not have the ability to use repeater systems with these. The advantage in a Marine Environment is that if you have line-of-site to commercial or public boating, you have a high degree of probability to be able to contact the boat. Your range and elevation are the limitations. Some of these Channels are allocate to Marine Phone Operators, I have never used these, but again these could be valuable.<br><br>National Park Frequencies are again (many times) in the VHF frequency sets. Isle Royale MI has three frequencies 168.525, 169.675, 170.350Mhz. So neither the HAM radio or Marine Radio will cover these.<br><br>HAM radios generally allow the user to Monitor frequencies outside of the broadcast range, so you can monitor Park Service or Marine frequencies but not broadcast on them. As kf4ebp noted radios can be modified to broadcast out of the allocated frequency and it is illegal to do so EXCEPT in a true emergency.<br><br>NOAA Weather is broadcast on 7 VHF frequencies<br>162.550<br>162.400<br>162.475<br>162.425<br>162.450<br>162.500<br>162.525<br><br>HAM 2m and Marine Radios can receive these frequencies.<br><br>The ARRL has an assigned Simplex 2m frequency for its Wilderness Protocol. They advocate monitoring 146.520MHz starting at 0700 local time for 5 minutes, then monitor every 3 hours on the hour. I have no ideal how widely this is practiced, and you are of course limited to line-of-site contacts. But presumably if you could schedule your emergencies on moutaintops and your local HAM community was listening.....<br><br>I have an ICOM 2GAT Ham 2m radio (very old model w 7 watts output power) and a Raytheon Marine handheld. The ICOM is an excellent product, I wish I had purchased an ICOM Marine radio as the accessories and support are much better.<br><br>More National Park Frequencies to monitor can be found at this site:<br><br> National Park Radio Freqencies