Under 47 CFR 80, Marine radios used on land are "land stations" and must be licensed and operated under those rules, which are quite restrictive. VHF marine radios for small craft are exempt under 47 CFR 80.13(c) from mandatory licensing but must explicitly follow the usage rules outlined in 47 CFR 80.89, which prohibit use while on land.
Now, if any club official has knowledge that VHF marine (or surplus police) radios are used at club events, that could make the club also liable for any fines levied by the FCC.
Of course, I wouldn't worry too much about this. The current Administration or a possible future Clinton Administration (heaven forfend) would be so gun friendly that they'd never want to risk their support base by making an example of a shooting club and would probably just give you a bye on it. Besides which, most shooting clubs have enough funds on hand that they can just pay a $20,000 fine out of petty cash.