Those ranges quoted are for aircraft thousands of feet above sea
level. The jamming range would be much shorter for boats, probably
10 miles or less.


aSSuming it's a linear relationship, I get 202 mile radius...




Not linear: for a ground level jammer,
The line of sight estimator for distance versus height above sea level
goes something like this:
distance n.m. = 1.2 sqrt (Height ft MSL)

...and of course that assumes that the emitter is at sea level, so if it
is at any appreciable height (or in another aircraft) then you have to
add the result of the same equation again!!

Jeff