Ascending to the surface

[RXTdiver]

In the online course it says, "Before starting my ascent, I should check my dive computer to be sure I’m within its limits."

What limits are they talking about?

 

[Cthippo]

It is talking about your No Decompression Limits, or NDL. Basically, being within your NDL means you do not need to do any decompression before you ascend.

While this is not bad advice, you should be watching your computer throughout the dive to be sure you are not getting into decompression, rather than finding out at the end.

 

[Vitesse2l]

If I've understood correctly that's probably asking you to check whether the computer is allowing you to surface directly without needing a mandatory deco stop.

Ideally you'd have been monitoring your computer throughout the dive and this wouldn't be a surprise when you come to the ascent. There's a difference between planning a dive to include decompression and accidental deco because you were not paying attention!

Good luck with the training.

 

[Scared Silly]

As others have said, within the deco limits so you can ascend directly to the surface. Or put another way: If your computer shows a screen you have never seen before you are most likely in deco.

 

[Jake 10]

A computer will keep track of your depth limits and will indicate if you need a deco stop and at what depth. For example; if you dive to 90ft your computer most likely will tell you to do a deco stop at 60ft for few minutes, and maybe another at 15ft for 3 min before surfacing. Shallow dives will not require a deco stop, but: It is good practice to do a 3 min safety stop at 15ft before surfacing. This allows you to check for passing boats before surfacing.

 

[Outbound]

A computer will keep track of your depth limits and will indicate if you need a deco stop and at what depth. For example; if you dive to 90ft your computer most likely will tell you to do a deco stop at 60ft for few minutes, and maybe another at 15ft for 3 min before surfacing. Shallow dives will not require a deco stop, but: It is good practice to do a 3 min safety stop at 15ft before surfacing. This allows you to check for passing boats before surfacing.

NDL is a function of time and depth, not just one or the other. It is entirely possible to go into deco on a relatively shallow dive, and it is entirely possible not to go into deco on a deeper dive. Although on a very shallow dive your dive time is more likely limited by gas supply and possibly thermoregulation.

 

[GreggS]

NDL is a function of time and depth, not just one or the other. It is entirely possible to go into deco on a relatively shallow dive, and it is entirely possible not to go into deco on a deeper dive. Although on a very shallow dive your dive time is more likely limited by gas supply and possibly thermoregulation.

Another factor is the gas one is breathing. A diver will have more bottom time before reaching NDL breathing nitrox than they will with air. And then all that depends on the algorithm of the computer being used. So many variables to take into consideration.

 

[EFX]

...and there are more factors: is this a repetitive dive (2nd, 3rd, 4th dive)? Was there a short surface interval? Is the dive deeper? Higher computer conservatism will have you going into deco sooner.

 

[BlueTrin]

As others have said, within the deco limits so you can ascend directly to the surface. Or put another way: If your computer shows a screen you have never seen before you are most likely in deco.

Probably better to read the manual though

Although most manuals aren’t very clear about what to do in case of accidental deco

 

[Angelo Farina]

Probably better to read the manual though

Although most manuals aren’t very clear about what to do in case of accidental deco

I think the instructions are very clear: do not ascend directly to the surface and respect the deco stop(s) shown by your computer.