Wow, that’s horrible advice from the dive center. Every course I have taken days you don not share computers. In my opinion, that’s a lawsuit waiting to happen. What if one of those instabuddies was diving multiple dives the day before or even that morning. They could have a very different NDL. What if you’re on nitrox and they aren’t. All it takes is one of them getting bent and then saying “so and so said we still had more time”.
Agreed completely. I've heard that from time to time and I'm just amazed that someone actually said it. I learned originally on tables, but even then, it was taught that if using a computer, use your own. There will always be variations from diver to diver. Could be small, but could also be significant. Regardless, trusting another diver, who I may have just met, with information such as this is a bit much to ask.
Tables are not that hard to understand, especially the SSI tables, which is just “follow the arrows”. Knowing tables helps you to plan a dive, but unfortunately that is usually overlooked in OW classes too. Tables also help with figuring out how long your surface interval should be. Computers give you your surface time but most don’t tell you how long your surface interval should be before the next dive. I can’t tell you how many times I’ve been on a boat and the DM would ask a diver how long do you need for your interval and the diver didn’t know.
That would depend on the dive plan for dive 2. Yes, you could find that on a table, but I could just as easily enter the planning mode on my computer. I can see what my bottom time would be right now, or in the near future.
Also, the other problem with not at least.understanding tables is that I see people dive a wreck and start in the deck then drop lower for the later part of the dive. Because they have no idea of what the NdL is at the deeper depth is, many times they end up in deco
They are both tools. While I was taught using tables, and my daughters were taught that as well, I really don't use them that much. It's just simpler for me to use the computer. The problem you describe above, doesn't really have anything to do with not knowing tables. It has more to do with not understanding the basics of decompression theory. There really is no problem hanging out on the deck for a bit, then dropping lower with either tables or a computer. With tables, you have a new max depth, to figure. Hopefully the dive time doesn't exceed. With a computer at least, the computer will recalculate. If the diver doesn't pay attention to the computer, then I really don't know what to say to that. Whatever tool you use, if you don't know how to use it, it's just not going to help you.
I can't recall the last dive I did where there was a diver without a computer. This includes OW checkout dives I did with my daughters. In fact, I'm pretty sure the last dive I did where not all divers had a computer was back before 2006 or so. And the sole diver without a computer then was me. Since then, I've converted and made sure I understood how to use these tools.