How to improve your buoyancy in scuba diving

If there is one skill that separates an average diver from a truly confident one, it is buoyancy. Good buoyancy control means you use less air, move more efficiently, protect the reef from accidental contact, and simply enjoy your dives more. Bad buoyancy means you are constantly fighting the water, kicking up sand, bumping into things and surfacing with half a tank left because you burned through your air compensating for poor trim. Here is how to fix that, starting from the fundamentals.

Why is buoyancy the most important diving skill?

Buoyancy is the foundation of everything in diving. When your buoyancy is dialled in, you hover effortlessly at any depth, you glide through the water with minimal fin kicks, your air consumption drops dramatically, and you become almost invisible to marine life. When it is not, you are the diver everyone sees flailing around, ascending and descending like a yo-yo, and accidentally destroying the coral with your fins.

During your Open Water course, you learn the basics of buoyancy. But the truth is, most new divers leave their OW with functional but mediocre buoyancy skills. It takes practice, awareness and a few specific techniques to go from "I can descend and ascend safely" to "I can hover motionless at 15 metres with no hands and no fin movement."

The good news is that buoyancy is learnable. It is not a talent; it is a skill. And like any skill, it improves with deliberate practice.

Are you carrying too much weight?

This is the single most common buoyancy problem, and it affects the majority of divers from newly certified to surprisingly experienced. Overweighting is epidemic in recreational diving, and it is the root cause of most other buoyancy issues.

When you carry too much weight, you need to put more air in your BCD to compensate. More air in the BCD means bigger volume changes with depth changes, which means more dramatic buoyancy swings. You end up in a vicious cycle: add air, float up, dump air, sink down, add air again. Your air consumption skyrockets because you are constantly adjusting, and your trim (body position in the water) suffers because the extra weight pulls your hips down.

How to do a proper weight check: at the end of a dive, with a nearly empty tank (50 bar), float at the surface with your BCD fully deflated. You should float at eye level. When you exhale, you should sink slowly. If you are sinking even while inhaling, you are overweighted. If you cannot get below the surface with a full exhale, you need more weight. Most divers need 1 to 3 kilograms less than they think.

A common rule of thumb for a 5 mm wetsuit in saltwater is roughly 10 percent of your body weight. An 80 kg diver might need 7 to 9 kg. But this varies with wetsuit thickness, body composition and whether you are diving salt or fresh water. Start light and add weight incrementally, not the other way around.

How do you use your breathing to control buoyancy?

Your lungs are a natural buoyancy device. When you inhale, your lung volume increases by about 3 to 4 litres, which is enough to make you rise noticeably. When you exhale, you become slightly negative and begin to sink. This is your primary fine-tuning mechanism.

The technique is simple but takes practice: breathe slowly and deeply, and use the pause between inhaling and exhaling to control your position. If you are drifting up slightly, exhale a bit longer and pause at the bottom of your breath. If you are sinking, extend your inhalation. Avoid holding your breath (the number one rule of diving) but do lengthen your breathing cycle.

Many new divers breathe too fast and too shallowly, which means they never get the full buoyancy effect of their lung capacity. Slow, deep, relaxed breathing is the key. It also reduces your air consumption significantly. A diver with good breathing technique can easily extend their dive time by 15 to 20 minutes compared to a fast breather at the same depth.

The goal is to reach a point where your BCD is set and you are making all fine adjustments with your breathing alone. Your BCD should not need constant inflation and deflation once you are at depth.

What is trim and why does it matter?

Trim is your body position in the water. Ideal trim is horizontal, with your body flat, your fins slightly elevated, and your head looking forward, not down. Think of it as streamlining yourself like a fish rather than hanging vertically like a seahorse.

Poor trim is one of the most visible signs of an inexperienced diver. A diver with bad trim is typically in a head-up, feet-down position, which means their fin kicks push water downward instead of backward. They move slowly, use more energy, and their fins constantly threaten the reef below.

To improve your trim, start with weight distribution. If your feet keep dropping, move some weight higher on your body. Integrated weight pockets in your BCD are better for trim than a weight belt, because they sit closer to your centre of gravity. Some divers also use ankle weights to keep their legs from floating up, but this is usually a sign that something else is wrong (typically too much air in the BCD compensating for excess weight).

Your arms should not be used for propulsion or balance. Tuck them close to your body or let them hang relaxed in front of you. If you are waving your arms to stay stable, your weight and BCD are not right.

How should you use your BCD for buoyancy control?

Your BCD (Buoyancy Control Device) is a tool for macro adjustments, not micro ones. Here is how to use it properly:

At the surface: inflate your BCD fully to float comfortably. This is not the time to practise neutral buoyancy.

During descent: deflate your BCD slowly and start your descent feet-first or in a controlled head-down position. As you go deeper, your wetsuit compresses and you become less buoyant, so you may need to add small amounts of air to slow your descent.

At depth: add just enough air to achieve neutral buoyancy, then stop touching the BCD. From here, all adjustments should come from your breathing. If you find yourself constantly adding and dumping air, you are either overweighted or making too-large adjustments.

During ascent: as you rise, the air in your BCD expands. You need to vent air progressively to avoid an uncontrolled ascent. This is critical for safety: an uncontrolled ascent is one of the leading causes of decompression sickness. Ascend slowly (no faster than 18 metres per minute, ideally slower) and vent air continuously as needed.

The key principle: small, infrequent BCD adjustments. Add or release air in short bursts, then wait 10 to 15 seconds to feel the effect before adjusting again. Patience is the difference between smooth diving and a roller-coaster.

Should you take the Peak Performance Buoyancy specialty?

The PADI Peak Performance Buoyancy (PPB) specialty is one of the most valuable courses you can take after your Open Water. It is typically 2 dives focused entirely on buoyancy refinement: proper weighting, breathing techniques, trim, hover drills, and precision control. If you have 10 to 30 dives and feel like your buoyancy could be better (it almost certainly can), this specialty will make more difference than any other course.

During the PPB course, you practise hovering motionless, swimming through hoops without touching them, maintaining a precise depth for extended periods, and executing slow, controlled ascents and descents. It is the course that turns buoyancy from something you think about into something that happens automatically.

For more on what to do after getting certified, check our guide to what comes after your Open Water.

What are the most common buoyancy mistakes?

Based on thousands of dives with students and certified divers, here are the mistakes I see most often:

• Carrying too much weight: already covered above, but it cannot be overstated. This is mistake number one.
• Using the BCD instead of breathing: if you are pressing the inflate/deflate button more than a few times during a dive at constant depth, something is wrong.
• Not doing a weight check: many divers just use the same weight they were given on their first dive and never adjust. Your buoyancy needs change as your wetsuit ages, as your diving improves, and between fresh and salt water.
• Diving in a vertical position: the seahorse position wastes energy and makes depth control difficult.
• Panicking and inflating on ascent: when you start rising unexpectedly, the instinct is to stop kicking and sometimes to add air. The correct response is to exhale, dump air from the BCD, and flare your body horizontally to create drag.
• Ignoring wetsuit compression: as you descend, your wetsuit compresses and you lose buoyancy. As you ascend, it expands and you gain buoyancy. You need to compensate for these changes, especially during the first 10 metres where the pressure change is greatest.

For a broader list of diving mistakes, read our 10 common diving mistakes guide.

The bottom line

Good buoyancy is the difference between diving and truly being part of the underwater world. It does not come overnight, but with the right techniques and deliberate practice, anyone can achieve it. Start by reducing your weight, slow your breathing, work on your trim, and consider the Peak Performance Buoyancy specialty if you want structured coaching.

At Dive With Lau, buoyancy work is integrated into every course and guided dive. Whether you are a brand new diver on your first dive or an experienced diver looking to refine your skills, we take the time to help you get it right.

Questions about your buoyancy? Get in touch with Lau. We can work on it together during your next dive.