Weapon of mast destruction

[DeusDeceptor13]

Buddy is trying to argue that weapon of mast destruction applies to both munchkins with ships in a fight..the card specifically says +2 to either side, or +5 if used against a munchkin who has a ship, or a monster that is a ship.

I feel it applies to simply one munchkin with a ship and stays at +5 and doesn't double to +10 because of another munchkin in the fight with a ship.

I've been drinking... Cheers!