Is there a reliable way to test your VHF range?

I have a 25 watt radio and a 3 db antenna. Although the antenna is mounted to the transom (not an a-frame) I am wondering how can I test its range so I know where my boundaries of communication will be to the mainland? Supposedly I should have 25 miles according to my equipment no? Anyone have any way of testing your vhf range without say being a nuisance or having to actually physically test the range? Are there some channels available that may possibly echo a signal back so you can test your transmission?

VHF range is basicly 'line of sight', although often a little better.
When calculating range you must include the height of the Antenna on the shore. Coast guard often have antennas mounted on high masts on the top of a hill or cliff. This gives very good range even with a Hand-held.
You must also consider that you can be land-locked, in a small cove or under a cliff.
There are no facillities for testing range other than talking to other vessels, this will only give an indication of range to that particular vessel as another vessel may have a different antenna height or less sensitive radio.
I am sure that a short test-call to the Coast Guard would not be a problem.

Cheers,

Mark.

Thank you. That seems to make the most sense. Just didn't know if there is say a specific channel you can ping your transmission from.

cheers,
boatster

As far as Radios go it would seem that Marine VHF Radios on 25 Watt are considered to be very powerful radios indeed.

It would seem that Land Radios have much less power.

Because the sea is generally flat, except for the waves and the curvature of the earth you should get a long way on your Radio. Even if you can't speak to the coastguard you should be able to speak to another ship.

I'm only guessing but my handheld is good to about 10 miles to receive the coastguard. But not other ships. It must be that the coastguard have a massive aerial or maybe even transmit at higher that 25 watts.

My main problem is actually hearing the radio over my noisy two stroke engine.

Regards Biggles