Category Archives: Apnea

Sporasub SP1 Freediving Computer / Watch Review

The latest addition to my growing list of freediving kit is my new Sporasub SP1 freedive computer. This helps me with one or two of my frustrations which I am sure that I share with other new freedivers. How deep am I going? How long am I down for? How many dives have I done? One of the reasons I prefer freediving over scuba is the simplicity, so I really don’t want to clutter my body or my thought processes with anything more than i have to.

This is the perfect tool for me; as well as satisfying my curiosity, I con now benchmark one day’s diving against the next to see how my performance is changing over time.

Why did I go for the Sporasub SP1? Well, I started at the bottom of the price range (this cost £145 or $225), and worked upwards, luckily my criteria were satisfied by this one, which happens to be the cheapest on the market. It was also dropping in prices as the new Sporasub SP2 is available with wireless connection and heart rate monitor, and I wanted to snap one of these up before they stop making it.

Sporasub SP1 Time display mode

Sporasub SP1 Time display mode

What I wanted was simple:-

  1. Something that automatically kicked in to log dives without me having to remember to press any buttons.
  2. Something that allowed me to look at logs afterwards to see what I had done
  3. Something that logged surface time as well as dive time

What I didn’t want:-

  1. A scuba watch that also had a freedive function (watches with more than one button are confusing enough for me without having loads of extra functions I will never use).
  2. Something that relied on me having to press buttons before every dive (something else confusing that I can’t be bothered with).
  3. To spend double just to get extra functions that I won’t ever use unless I start training and competing at deep diving.
Sporasub SP1 Dive log Mode

Sporasub SP1 Dive log Mode, showing depth, water temp, and dive duration

What you get with the Sporasub SP1 freedive computer:-

  1. Dive mode automatically kicks in when the watch is submerged by 1.5m, you don’t have to do anything, it just starts logging straight away, even if the last time you looked it was just showing the time.
  2. When you get back to the surface it automatically starts to count surface time (you should be breathing up on the surface for at least as long as your last dive before you go down again)
  3. It logs dive time, dive depth accurate to 10 cm, water temperature.
  4. It saves these records for you to look at later, up to 199 of them.
  5. Depth warning, it will beep for 30 seconds when you reach a preset limit.
  6. Switch between sea and fresh water
  7. Other stuff you would normally get on a watch, time, date, stopwatch etc.

Things you might get on a more expensive computer that the Sporasub SP1 doesn’t have:-

  1. Wireless link to a heart rate monitor (like the Sporasub SP2)
  2. USB connection to download and analyse your dive stats and save them for ever more. (Sporasub SP2, Mares Smart Apnea, Oceanic Aeris F10)
  3. Time warning, multiple depth warnings, (Oceanic Aeris F10)
  4. hydration reminders, descent and ascent speeds (Mares Smart Apnea)

Summary – It works first time and every time, logging all the dives I do accurately (when compared to another borrowed dive computer strapped to my leash in a recent test dive).

I found the controls a little infuriating to start with when I tried to look at the dive starts whilst the screen was still displaying surface time. But this is more about my not remembering the instructions than design fault.

Who would I recommend this for? Any recreational non competitive freediver or spearo who wants an easy way to log their dives.

Who would I not recommend this for? More serious competition divers who want to really monitor things like ascent speeds, who need 10m warnings and want to monitor heart rates while diving. Those guys probably want to go for something more swanky, but they are going to pay in the region of £100 to £200 more for these functions.

Am I happy with the SP1? Yes. It looks cool too, though my wrists are so skinny I won’t be wearing it as a fashion accessory.

More breathing, and not breathing – Static Apnea Tables

Having attended the AIDA 1* course I am now suitably armed to undertake some structured practice. One of the things we learned about was apnea tables. These are a series of breathing exercises to help increase either carbon dioxide tolerance, or oxygen capacity. There are CO2 tables, a series of 6 breath holds to about 50% of your maximum time, with a decreasing gap between, or O2 tables, a good rest in between (maybe 2 or 3 minutes) but each hold gets longer. I have an app on my phone which talks me through the tables. They are best explained here

I use one called StaticApneaTrainer on Android.

It didn’t take long, a table per day on and off for a couple of weeks to get my breath-hold out of the water up to 4:47, which probably means I could top 5 minutes in the water as the cool water around your face helps lower your heart rate and floating around is more relaxing than laying on a bed. ( I learn’t that on the course too). I supplement this with stretching exercises, taking a full breath and reaching my arms above my head to stretch out my intercostal and back muscles. I don’t know, but I think this A/ helps increase lung capacity (maybe), and B/ means that when you take a deep breath these muscles are nice and loose because they are used to it and aren’t gobbling up valuable oxygen.

I’m convinced all these exercises help with sport in general, and my sport (rowing) in particular because any increased lung capacity, or tolerance to CO2 is going to help, and CO2 means acidic blood, so does it help with lactic acid tolerance too?

UPDATE! You don’t get far into freediving before you realise that there is so much more to it than how long you can hold your breath!….. see the next installment –

AIDA 1* Learning how not to breathe

My one day course was upon me, a trip to Newquay for the basics of breath holding and freediving safety. I had started to read up on it all, quite a lot of reading actually, the science of breath holding and how to improve it. We were told not to do too much practical stuff before the course though. The idea of the course is to start from scratch and teach everything in a safe and controlled way.

I must admit I did do a bit of breath holding beforehand, but why not, it has been a bit of an interest on and off since I was a teenager. Apparently lots of kids do it, so I’ve always known that if I have a few days practice I can up my breath-hold time a bit.

The course was briliant and I never realised that something so simple could involve so much science.

The things that will always stand out from this course are the following:-

  • The urge to breathe comes from a build up of carbon dioxide, not a decrease in oxygen supply.
  • The urge to breathe – those contractions of the diaphram and chest muscles that tell you that if I don’t breathe soon I will die! These are an indicator of a build-up of carbon dioxide and not necessarily a lack of oxygen.
  • Don’t hyperventilate – This doesn’t increase your oxygen supply, only decreases your carbon dioxide, which in turn means that you are shifting the goalposts, hiding the urge to breathe until it is possibly too late.
  • Chest contractions – these should be a friendly indicator that you have high carbon dioxide levels, but it doesn’t mean you have to breathe now, your oxygen reserves might still only be 2/3 or even 1/2 depleted.
  • When you surface don’t do a huge exhale. This could rid you of the very last of your oxygen supply and result in blackout, breathe out just half, then in again, and then take a few deliberate half breaths until you are back to normal.

There was a lot more advice and instruction than this; how to buddy up during static apnea practice (breath holding on water); the correct things to wear; correct weighting; equalisation of pressure; physiology of your ears and sinuses; looking out for your buddy; the signs that something has gone wrong and loads more besides so don’t take this blog as anything like a substitute for doing the course itself  – DON’T TAKE MY SECOND HAND INFO AS DEIFINITIVE AND EXHAUSTIVE – I am still a novice and just relating what I got out of the course, I’m not trying to teach it to anyone else. If you are at all interested I’d say go and do it yourself – – Tell them I recommended you and I might get a free drink bottle on my next course!

Ian who instructs the course always maintains that he can help improve a beginners breath holding quite substantially with a day of instruction. I was already a little practiced, but even I manage to up my maximum hold from just about 4 minute to 4:18, I was impressed, and looking forward to doing a bit more soon. The guy that was with me on the course, who was already an experiences spear-fisherman, upped his from about 2:40 to 3:20. He was chuffed too, having previously struggled to better his time.

So this course left me wanting more, but still not properly experienced in open water freediving, so as the day drew to a close I was already looking forward to the next course; AIDA 2*, open water, down a rope, looking at fishes, a real freediver!

UPDATE! You don’t get far into freediving before you realise that there is so much more to it than how long you can hold your breath….. see the next installment –

Freediving Course Booked

So a little bit of research unearthed an outfit in Newquay, FreediveUK. Just the ticket; run buy a guy who has been on TV, coached big wave surfers how on to hold their breath whilst being rolled over a shallow reef by 1ooft breaks, and more importantly for me, he’s on of a very small number of freediving instructors in the UK.

FreediveUK teach AIDA courses, an abbreviation of the French originating Association Internacionale de Apnea (or something like that). Apnea is holding your breath, as in sleep apnea, when people snore so badly they suffocate, there you go.

So I booked up for a 1 day AIDA 1 star course. £125, a lot of money for a few dips in the pool, but I’m going to do this properly.