Before heading out on any trip, you should have plenty of basic electrical materials to be able to put together any type of emergency
rig, ground or antenna system.
Having these materials will also allow you to do some basic trouble shooting. Reduce everything to it parts
and go from there.
First things first. You did a test of your radio in some other boat...you should have taken that radio and tried in your boat.
But...if cannot...begin at the beginning, since using you radio on another boat is some proof that the radio is OK..
1. Put together a dipole antenna and use it directly with your radio. It should be fool proof. This will allow you to isolate and ignore your boat's counterpoise/antenna system. Try that. If OK, this proves that your radio is OK.
[Quick note: a great piece of emergency
to have is a short length of coax, that you have cut and then split into its outer braid and inner conductor. You can use this to create any type of dipole and many other types of antenna's]
2. Then...next step. Try using the dipole with your tuner. If OK, then tuner and radio are OK.
3. Then....counterpoise. Since you have the KISS, let's use that. Connect to the counterpoise
leg of your dipole, using your tuner.
Is that OK?
4. After this testing, you will know that your radio, tuner and counterpoise
are OK. Next.....you can probably guess.....your antenna.
Hope this helps