Even in the Florida keys, and I've only been there a few times and that was ages ago, so I certainly didn't sample all operators, no dives were restricted to less than 45 mins boat-boat. But they measure that time as starting when they say people can jump in and ending with everyone back on the boat, de-kitted and sitting down.
I once (at Key Largo) had an insta-buddy who was unbelievably slow in getting ready, so we finally jumped into the water a full 10 minutes after the last other person. Then he took an age on the surface swim up the boat to the mooring line, which was where we were to go down. Once he arrived at the mooring buoy he told me he couldn't go on. He looked dreadful, so I spent the next 7 or 8 minutes towing him back to the ladder, where the boat crew took over. THEN I started my dive. I had been down barely 20 minutes when the recall signal sounded. A prudent diver never ignores the recall signal, even if he has a strong suspicion what's behind it, so back up to the boat I went. Everyone else was aboard, and the crew made it very clear I was holding up the entire operation.
To be fair to the crew, they had a draconian schedule imposed on them, and if they failed to meet it they were simply fired. But they showed their understanding and gratitude by inviting me on several more dives that week, unofficially and with no paperwork or money going through the office. Two of those dives were particularly memorable - well, one was barely memorable, as it was a night dive that concluded with lots of free beers afterwards as we slowly cruised home. The other was testing out a potential instructor, but I'll leave that one till later.
I don't know of any dive operation here that imposes a time limit of less than 45 minutes, which is measured from when the divers submerge. And several impose no time limit at all - I have had dives on the standard Blue Hole trip lasting 1hr 20mins, and my longest local dive with another operator has been 1.5 hours (my longest with my own operation was just under 3hrs, but that's another story). But remember that sea conditions and experience levels always have a bearing, sometimes quite considerable.
I once (at Key Largo) had an insta-buddy who was unbelievably slow in getting ready, so we finally jumped into the water a full 10 minutes after the last other person. Then he took an age on the surface swim up the boat to the mooring line, which was where we were to go down. Once he arrived at the mooring buoy he told me he couldn't go on. He looked dreadful, so I spent the next 7 or 8 minutes towing him back to the ladder, where the boat crew took over. THEN I started my dive. I had been down barely 20 minutes when the recall signal sounded. A prudent diver never ignores the recall signal, even if he has a strong suspicion what's behind it, so back up to the boat I went. Everyone else was aboard, and the crew made it very clear I was holding up the entire operation.
To be fair to the crew, they had a draconian schedule imposed on them, and if they failed to meet it they were simply fired. But they showed their understanding and gratitude by inviting me on several more dives that week, unofficially and with no paperwork or money going through the office. Two of those dives were particularly memorable - well, one was barely memorable, as it was a night dive that concluded with lots of free beers afterwards as we slowly cruised home. The other was testing out a potential instructor, but I'll leave that one till later.
I don't know of any dive operation here that imposes a time limit of less than 45 minutes, which is measured from when the divers submerge. And several impose no time limit at all - I have had dives on the standard Blue Hole trip lasting 1hr 20mins, and my longest local dive with another operator has been 1.5 hours (my longest with my own operation was just under 3hrs, but that's another story). But remember that sea conditions and experience levels always have a bearing, sometimes quite considerable.
