The Editor says: The dive planning table — most of you probably spent a fair amount of time during your Open Water certification trying to make sense of all those numbers. But once you got your card, you handed the planning over to your dive guide and your dive computer, and little by little, the whole concept drifted further and further away. With winter marking the slow season for diving, we've reprinted an article by ODYSSEY DIVERS instructor. Take this as a refresher on why dive planning still matters! Extended link: Odyssey Divers Facebook Group.
ODYSSEY — the Odyssey — one of the two most important epics of ancient Greece, composed by the blind poet Homer. It carries another meaning as well: a long journey of discovery, an epic quest. Every moment of learning, every departure, is a journey in itself. Life is a journey, and so is every dive. That's the spirit behind Odyssey Divers.
Wang Yu-Jun is a wandering dive instructor — teaching abroad every winter, returning to Taiwan only in summer. Penghu, Xiaoliuqiu, Northeast Coast, Orchid Island, Green Island, Kenting, Koh Lanta, Sipadan, Tioman, Perhentian, Malapascua, Moalboal, Puerto Galera — these are all places he has traveled through and lived in. His favourite of all is Koh Lanta, the place he finds himself returning to every winter without fail.
What Is a Dive Planning Table?
Dive planning — it's a term every beginner hears when they first learn to dive. And even if you don't remember the term itself, you'll recall that before every dive, your instructor would brief you on the site, the entry method, the route, the maximum depth, the dive time, the turn-around pressure, the safety precautions, potential in-water emergencies and how to handle them… right? No? Then either you weren't paying attention in class — or your instructor wasn't teaching it properly.
During the entry-level Open Water course, all of this should be covered. A dive plan is critically important for every dive — it's what ensures everyone knows what to watch out for underwater. But how many people truly grasp why it matters?
At first, you might know the what without understanding the why. For a beginner, being able to go from zero to controlling your own ascents and descents within just four dives — and then managing neutral buoyancy well enough not to harm marine life or yourself, and handling basic situations without creating new problems — is, in my view, a far more important foundation than being able to fluently read and execute a dive plan.
That's why, at the beginner level, the execution of the dive plan rests largely with the instructor, not the student. As a result, most beginners never fully appreciate how important planning really is. But as you accumulate dive travel experience, log more dives, and grow more comfortable with in-water control — that's exactly when you should start paying closer attention to dive planning.
Diving conservatively is always the most important principle. The ocean will always be there. You only have one life.
In the broad sense, a dive plan begins the moment you decide you're going diving. If you own your own gear — is everything in order? Has it been so long since your last dive that servicing is needed? How do you get all your equipment to a dive site, whether local or abroad? Is your physical condition suitable for diving? Are the conditions at the site safe enough to enter the water? Do you have a backup site? What's the quality of the local dive shop? What's the level of the dive guide? Accommodation, transport, food — there's so much to think about, it can feel overwhelming.
In the narrow sense, a dive plan covers the conditions at the entry point (swell, current, visibility, etc.), how to enter and exit the water, the dive route, the purpose of the dive, bottom time, maximum depth, planned turn-around pressure, safety stop, decompression stop, the buddy system, buddy separation procedures, contingency scenarios, problem-solving, and whether your buddy is physically and mentally fit for the dive — whether they clearly understand and agree to the plan. In essence, it's a full mental walkthrough — from the moment you enter the water, through the entire dive, all the way until you're safely back on the boat or shore. Everyone knows what to watch for, what to be mindful of, and no one is left panicking and helpless when something goes wrong.
Before dive computers existed, divers had to consult dive tables to calculate and plan their depth and time profiles. Bottom times were relatively short, because looking up no-decompression limits on a physical table in real time underwater was impractical — and even if you could, the results weren't precise. With advances in technology, recreational divers have come to understand the importance of the dive computer, and most carry one. Watching your computer display maximum depth, current depth, dive time, and no-stop time makes every dive significantly safer.
PADI Dive Planning Table
Today's dive computers perform continuous calculations as depth changes, allowing divers to know at any moment how much no-stop time remains at their current depth. However, over-reliance on the dive computer leads some divers to push its numbers to the absolute limit — believing that as long as they surface within the safe zone, everything is fine.
Of course, if you end the dive within the computer's safe parameters, the computer reads it as safe. But does that guarantee your body is actually fine? In fact, as most Open Water courses discuss, no existing dive model can guarantee complete safety — even if you ascend or end the dive within the prescribed time and depth limits. The message, in other words, is this: dive more conservatively, dive more safely.
For recreational diving, you should always plan within no-decompression limits (if you've forgotten what that means, go back to your textbook or ask your instructor). Where possible, ascend to shallower depths earlier in the dive to allow your body to off-gas excess nitrogen sooner. Even on a recreational dive, planning your route to include periods at varying depths during the ascent is relatively safer than shooting straight up. As you approach the end of the dive, a 3-minute safety stop at 5 m is required — again, to allow the body to off-gas excess nitrogen (emergencies excepted).
One more important reminder: after completing your safety stop, as you ascend from 5 m to the surface, you must control your ascent rate carefully. Think about it — which involves a greater pressure differential: ascending from 10 m to 5 m, or from 5 m to the surface? I'm sure you know why. Don't? Go ask your instructor — or ask me. This is exactly why I always emphasise and drill neutral buoyancy control in my classes.
A dive plan enables the dive guide and the diver to communicate beforehand, exchange essential information, and make sure the diver understands the site conditions and the flow of the dive. It also gives the guide a chance — through conversation — to gauge the diver's current condition and anticipate any issues that might arise underwater. This avoids the need to try to communicate when you can't speak, helps problems get resolved smoothly, and gets everyone back to the surface safely.
So — does dive planning matter?
The video below was found online. There are several mistakes in it that could have been avoided. Can you spot them?
Does neutral buoyancy matter? Does controlling depth and time matter? Does regularly monitoring your own and your buddy's pressure gauge (SPG) matter? Does the buddy system matter? Does the quality of your dive guide matter?
Does your own life matter?
