Jun 2015

Diving in Trim. Part 2

By Mike Waddington

A diver who has perfect trim will be horizontal in the water, their fins should be higher than the rest of the body but kept flat, and the diver should be extending their arms outwards. Although it is very easy to put into words how a diver should look underwater, in practice it is not so easy. The best way to perfect your trim is to get into the water and get practicing. Pools are great for this as you do not need to worry about deco limits, and being so shallow means that your air will last a long time.

Below is a guide on how different parts of the body should be in order to attain that horizontal, streamlined position known as trim.


The torso is key while trying to find perfect trim. You should arch your back and keep your shoulders pulled back. This may at first lead to minor aching back after a 45 minute dive, but this is normal. It won’t be long before you can hold that position for hours without any issues. It is common for new divers to ‘fold’ themselves from the stomach, making the diver look like an ‘A’ shape. When in this position the diver might believe they are facing down, but in reality their legs are kicking them to the surface


While diving you tend to go in the direction that you are looking in. Although there are times where you will want to look around you, most of the time you should be looking straight in front of you. This extends your spine and helps keep your body horizontal.


Whenever you dive your legs and fins should never be below the horizontal line of the body. The best position is to have the knees bent at a 90 degree angle, or as close to that as possible. You should try to keep your fins parallel to your horizontal body line, to avoid what is commonly known as ‘rabbit ears’ (fins sticking up create unnecessary drag). It will take some time to get used to keeping your legs held up, but after a while it becomes easy. Keeping our knees bent upwards allows you to use a wide variation of propulsion methods, such as modified flutter kicks or back finning. Keeping the fins high also reduces the risk of them accidentally knocking into anything or stirring up the bottom.


Your backside actually plays a bit part in keeping your body horizontal and keeping your legs up. To do this you need to clench your butt cheeks together, almost as if you are trying to hold a coin between them. This will help avoid dropping your knees and it will keep your thighs in line with your torso.


While diving your arms should be held out in front of you, roughly at the same level as your stomach, or just below. Because most divers wear dive computers and compasses on their wrist, all you need to do is quickly glance down to see all your dive information. Extending the arms outwards also helps keep the body in line.

Trim Check and Practice

Once you have understood how you should look in the water, and what you need to do with your different body parts, you need to do a trim check. This involves getting into the water with your buddy, and trying to hover in trim while without moving at all. This is harder to do than it might sound as most divers are subconsciously using their fins or hands to stabilize themselves during a dive. Your buddy can help correct your position if anything needs correcting. Once you are hovering you should then see if you can stay stable, or if you start leaning. If your body leans in any direction then you need to adjust your equipment or weights until you can stay stable.

You should also practice different fining techniques and see if you stay in trim while moving around. It is a good idea if your buddy has a camera with them, and takes photos or video footage of you, so you can see first-hand how you look in the water, and what adjustments you need to make.

It may feel unnatural at first, and it certain body parts might even ache after being in trim for a while, but after a while your body gets used to the position and before you know it, you automatically put yourself into a proper trim position without thinking about it. Although ideally you will be completely horizontal underwater, if you find that this is too difficult or hurts anywhere, being slightly heads up is ok, but keep practicing being horizontal, and after a while it will be easy.

‘Diving in Trim. Part 2’ was written by Mike

Related Blogs: Diving in Trim Part 1

Photo Credit: Sirius Diving Mexico

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Mike Waddington

I first discovered diving in 2008 after going snorkeling on the Great Barrier Reef in Australia. After trying diving at a flooded quarry in England I decided to head out to warmer more interesting waters in Thailand where I ended on the Island of Koh Tao completing my Open Water course. Instantly addicted with money to spend and plenty of time on my hands I decided to continue until I became a Divemaster so I could live what seemed as the perfect life.

After that I headed to the Caribbean to an island called Utila to complete my instructor course, I spent several months out there completing the MSDT internship, teaching students and leading dives. This is also where I discovered my interest in the technical side of diving, taking part in equipment repair courses and learning about blending gasses and running compressors.

With all my new qualifications it was time to head back to where it had all started, Back to Koh Tao where I intended on living the dream. Once I arrived I quickly found a job and started teaching straight away. During my time on Koh Tao I took part in all many technical diving courses, learning how to dive with re-breathers, in caves and even going down to 90m/300ft!


PADI Master Scuba Diver Trainer
PADI/DSAT Tech Deep Instructor
PADI/DSAT Gas Trimix Gas Blender
PADI/DSAT Trimix Diver
TDI Intro to Cave Diver
TDI Advanced Wreck Diver
TDI Inspiration rebreather Decompression Procedures
PADI Professional Videographer
BSAC Compressor Operator
TDI Equipment Service Technician

Dream Dive Locations:

Silfra, Iceland
Cenotes, Mexico
Chuuk Lagoon, Micronesia
Ice Diving in Russia