You're right that the options you've mentioned may not be expensive -- though they're intended for installation in a vehicle, with relatively easy access to repair / replace as necessary.Hi Kris,
Sure, in case of 3G data transfer, antenna must be fixed above high tide level.
Yacht's wind turbines, voltage regulators and batteries aren't very expensive, but definitely will add some extra costs to the project.
PoE is the standard an cheapest way, but if camera s is 100+ m far from an Ethernet switch and PoE injector - things becomes more complex and expensive too.
I agree regarding vandalism and equipment stealing... Unfortunately, it's not possible (or VERY expensive) to make the solution 100% vandal-proof.
This installation is fixed, and space is at a premium. Even if you COULD find somewhere to mount the antenna and solar/wind system, you're going to have trouble finding a place to store the batteries.