.... we dont need a U/W hunter card to board a spear-fishing charter?
No you do not need a specialty card or course card to board a charter. But on most every boat you will need a fishing license along with any species 'endorsements' (ie lobster) before you are allowed to hunt. Some boats do carry a captain's license that would exempt you personally from holding a fishing license, but it is extremely rare on dive boats. I've never found one that does.
....I mean the C-card then doesnt really do anything for you then right?
Well you still need a C-card to get manifested on a scuba dive charter boat. But if you freedive without tanks, you technically don't even need a c-card. Although you would still possibly need a fishing license if the boat doesn't possess a captain's license. If the perfect boat is available that has both a captain's license and lets you freedive, then you don't need a c-card nor a fishing license, just jump in and shoot a proper fish.
But for 99% of all the scuba dive charter boats in Florida, you'll need the correct C-card (corresponding with planned depths, ie AOW,EAN,tech), a valid fishing license (with endorsements) and as always permission from the captain to bring a speargun on board. Some captains don't allow spearguns. :mooner:
I also suggest new hunters, take a class or shadow an experienced spearo to learn the sport. There is nothing as brutal like being yelled at when you bring a protected fish, short fish, or trash eating fish back on the boat. Learn before you splash what fish you can target.
This was last Thursday's dives off Jupiter. It's a great sport!