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.