I have never had to show a card on a boat where they expect the divers to know what they are doing. In Lake Erie, I've never shown a card to Osprey. In Monterey, they never asked to see one. I filled out the paperwork on line, showed up at the dock with my gear, my name was on the manifest so they let me dive. Florida, Bonaire, and Puerto Rico where they get a lot of vacation/tourist divers, they wanted to see a card at the office but not on the boat.
In the St. Lawrence same thing. The boat captain didn't care about c cards. Shop made the arrangements and booked the dives. Passport? Oh yeah. Since we were diving a mix out of Brockville of Canadian and American side wrecks.
As for planning, be back with 500 PSI or 1000 PSI is not a plan. In Erie we know each others SAC rates and base the plan on those along with the depth, time, mix, and if we want a little deco to be part of it. I like diving Erie with the boat I do because having a buddy is not a requirement. Ok if you do, but if you don't and you are on that boat they assume you know the game and don't need to be told you have to dive with someone. If you choose not to, no problem.
Last time I was out with them I wanted to shoot photos. A group books the whole boat and sends out emails that we have X spots. If you're quick you get one. You send your money, show up, get on the boat and dive. I didn't even fill out a waiver because they know it's not worth the paper it's written on and can still be sued. The boat's a taxi.