Safer Diving: Always Have a Backup Plan

Safer Diving: Always Have a Backup Plan

This is the first in a three-part article series about emergency planning, this one will cover personal planning, the second will cover the dive emergency backup plan, and the third and final will cover situational awareness.

Scuba diving is a fantastic sport, one that allows for total immersion (no pun intended), leaving the world and everyday troubles behind.

But the serenity and zen-like state of diving shouldn’t prevent you from taking steps to ensure our safety.

One of these is to make sure you have a backup plan in case something goes wrong. This shouldn’t be a cause for over-anxiety and stress, but rather be seen as a dose of healthy, timely paranoia.

It’s to ensure that you can do our dive with peace of mind knowing that if things should, against the odds, go wrong, you’re covered.

Bring spares of anything critical

Rich Carey

A small collection of key items, such as spare O-rings in varying sizes, fin straps, mask straps, dive computer batteries, a few wire strips for attaching gear, and some duct tape. Put together in a small box can go a long way in making emergency repairs on-site if something fails.

And it can mean the difference between calling off a dive because a fin strap breaks, and actually getting to do the dive you packed your gear for.

A spare mask in a BCD or drysuit pocket is always a good thing to bring along on your dive, in case you lose your mask somewhere where you cannot retrieve it.

Have a backup plan for your dive computer

A bit of bad news: dive computers sometimes fail. Most often, what happens is that it simply turns off, perhaps never to come back on. And this can happen during dives as well as between dives.

There is a standard procedure for handling this, which is to end the dive immediately and to abstain from diving for the next 24-48 hours.


However, if you’re on a diving holiday or a liveaboard, this is a very strong penalty to pay for a malfunctioning piece of hardware.

Therefore, always dive with a backup watch

A simple, analog dive timer (also known as a watch) and an analog depth gauge can suffice in this role and can allow you to fully log the dive. It’s still highly recommended that you finish the current dive as soon as possible, but at least a watch and a depth gauge would allow you to do subsequent dives.

Another option is to simply dive with two dive computers, one main and one backup, allowing you to switch to the backup should the main one fail. Make sure that you bring both computers on all dives, though, so as not to build up a misleading consecutive dive profile.

Know the maximum time and depth of your dive


For deep dives, knowing how deep you plan to go, and for how long your maximum dive time is can make the difference between a safe dive and a troublesome one.

I always note down the maximum time and depth of a dive on a wrist-mounted writing slate that I bring with me (from the standard dive tables we all got when we took our first dive course).

Should my computer fail, I can use this, and my dive watch with a built-in depth gauge to make sure I end the dive in time.

Some divers have allowed dive computers to make them lazy. So they simply put one on, plop in the water, dive to a depth that suits them and the computer, and bubble around until the computer tells them to resurface.

While modern dive computers are sophisticated enough to allow this, and generally very reliable, I don’t recommend losing your mastery of the basics. Use a dive computer as an extra level of safety to add to your portfolio of skills, not a substitute for getting it right.

Manage your air

No, this isn’t about flatulence. Rather, it is about having a plan for your cylinder’s air. Use a few dives to get a good idea of your Surface Air Consumption, or SAC.

Knowing this then allows you to plan your dive according to depth and time. Because you know how much air you’ll need to bring on any given dive in order to make it back with a bit to spare. Of course it’s intrinsic to your backup plan that a buddy with more air to spare can give you a hit of theirs in a pinch.

Jon Milnes

For most shallow dives in the open (non-overhead environment), the usual rule of thumb is to start your accent when you have 50 bar left in your tank.

For more demanding dives (deeper, with stronger currents, or in an overhead environment), the tech diver’s rule to thirds is a good way to go: go out on a third of your available gas, return on the second third, and have a third in reserve.

So for a 200 bar tank, that would mean you’re turnaround point, or the point where you’re furthest away from your planned exit point, you should have about 130 bar left. And by the time you reach the exit point itself, you should have 70 bar left.

This may seem very conservative, but it ensures that a sudden increase in current or other unplanned incidents won’t see you sucking on an empty tank.

Get your head in the game

Before going on a dive, especially one that you’d consider demanding in relation to your experience level, make a conscious decision on your limits. Any good backup plan takes into account time and depth, springing into action when actual limits are crossed.

Just because the dive site gives you the option of going to 35 meters doesn’t mean you have to. And just because the dive is set to a maximum time of 1 hour doesn’t mean you can’t call off your dive after 45 minutes.

Just like it’s OK to forgo a dive all together if you’re not up for it.

Never do a dive, or any part of a dive, because everyone else in a dive team is doing it. Too many dive accidents are a result of people ignoring that little voice in their heads that tells them to not do something.

So check in with that little voice, and keep your attention tuned to it.

How is your backup plan?

A few simple precautions can make a big difference for your safety during a dive. Everything from simple equipment failure that has little more consequence than the annoyance of an aborted dive, too much more dire results, can all be avoided if you take a few precautions during our dive planning.

Do you always have a backup plan when you go diving? It’s not that many divers that really does the whole plan but everyone could strongly benefit from planning a few steps forward.

Tell us about your “backup plan”-steps in the comments below!

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