Reasons one marine handheld VHF transmitting at 1W has further range than

[Grant]

one transmitting at 2.5W? My Uniden MHS050 marine VHF cannot be heard by coastguard transmitting at 2.5W at a distance of about 15km while my CobraHH475 is heard clearly (4bar) transmitting at 1W (low) from the same spot. Both being hand held in a Kayak. How can that happen? Uniden say the VHF radio is working fine

 

[RichardC]

You might try using a Signal strength meter, to check the output. There could be several possibilities. Including the tuning of the frequencies of the USCG station. Or the person monitoring the radio, heard but didn't immediately respond to the first call because they where occupied momentarily on a different channel. But then heard the other call and responded. and when ask how he/she heard you, gave you correct information.