Taking it steady...
/It is really exciting to hear that we will all be able to visit the underwater world again soon. This most recent lockdown has been my longest gap between dives in over 30 years, and I am certainly really looking forward to breaking this "drought."
However, I think it is worth mentioning a few key safety points before we all dive back in. This is generic advice, so not all off it will apply to everyone, but please feel free to take those bits that are relevant to you.
1. Water Temperature
Most of us will be doing our first post lockdown dives at inland dive sites. These offer ideal conditions for our re-entry, but it is important to note their water is at its absolute coldest in late March/early April. Typically this will be around 4°C (fresh still water doesn't really get colder than this). The BCU suggests that immersion in this gives only 15-30 minutes before the victim becomes exhausted or unconscious, albeit with individuals that are not wearing any protective equipment.
Of course, we wear exposure protection when we are diving, and this allows us to operate in relatively low water temperatures without becoming hypothermic. This assumes that you are wearing the correct equipment and it is functioning correctly. Putting up with a leaky drysuit may just be uncomfortable in summer, but can be physically dangerous when the water is cold. My own belief, and I should stress that this is mine alone, is that wetsuits of any description do not provide sufficient thermal protection at these temperatures, and should not be considered adequate.
During more normal times, most of us that dive over the winter dive throughout the year and will have been diving as water temperatures dropped. The lockdown has prevented this and we will not be acclimatized. Expect the water to feel physiologically colder and plan shorter dives until your internal "thermostat" adjusts.
Lastly, in our previous normal times, we could escape inclement weather and rewarm post-dive in the excellent facilities at Capernwray. Social distancing rules now prevent this and we need to be more self-sufficient. Practically, travel in your undersuit to avoid needing to change outside. Consider bringing extra warm clothes, and be prepared to curtail any subsequent dives if you cannot get warm.
2. Equipment Issues
Most of us are aware that breathing from our regulators at the surface in cold weather will often cause free flows. This is true even with regulators that are designed to work in very cold water. In general, it is best practice to avoid doing so. Similarly, avoiding using the second stages' purge buttons, either on the surface or underwater, prior to or during the dive can help prevent ice from forming. Any activity that causes the gas to flow faster in the breathing system is potentially problematic when water and air temperatures drop.
While on the subject, not all regulators are designed to work in cold waters, and some work better than others. Please check that yours is suitable!
Regulators require an annual service. This is because the first stage seals using a soft polymer seat that is pushed onto a metal cone by spring pressure. This spring pushes whether the regular is used or not and can cause scoring on the soft seat. This allows pressure to "leak" past the HP seat and increases the pressure downstream, which ultimately will force open the second stage, causing a freeflow. Most of us have had an enforced hiatus from diving, but unfortunately, our regulators will still need servicing before we venture underwater with them again.
3. Mental and Physical Readiness
It is inevitable that ALL our skills degrade if they are not used. Our brains and bodies automatically retain the most relevant information that they need to carry out tasks while discarding infrequently or less recently used motor skills and knowledge. Logically, we all know this as if we practice something long and often enough, it becomes automatic, but we are often slower to recognize that when we stop practicing, we lose this.
This is directly relevant due to our lack of recent diving. How we deal with this will vary from individual to individual. A diver with a lot of experience will lose skills less quickly than an experienced diver. There is some evidence that even with experienced divers, rarely used skills (which typically describes most emergency skills) that are not regularly practiced will still fade.
If you do not have the specific skills needed to dive safely in these extreme conditions, you need to seek out training. The obvious example here is using a drysuit, but this could also include dealing with reduced visibility, surface temperatures, and more complicated dive planning. It may be the case that you may feel safer diving with an instructor for a few dives to get you back into it.
So, it boils down to you carrying out an honest self-assessment of your ability to carry out a dive safely. This needs to include whether you have the skill currency to deal with an emergency, should one arise during the dive. If the answer is no, then either modify your dive plans or seek some kind of structured refresher.
It is interesting to note that most instructors have not been teaching over the lockdown, and their instructing skills (along with their diving ones) will need some refreshing. In this circumstance, perhaps we should choose to teach courses that are less demanding until the fluency returns?
Of course, where agency standards or procedures apply, these would supersede any advice above.
So where does that all leave us at the end of March? The best advice is to ensure that you take your return to dive seriously. You will be diving in very cold water, which in itself, is a very challenging environment. You will probably not have dived for some time and the key skills that you would need in the event of an emergency are likely to be rusty. Your dive planning needs to take all this into account and be conservative.
You owe it to yourself and your enjoyment of our wonderful activity to load the deck in your favor by ensuring you wear adequate exposure protection, plan shorter dives, and make sure your skills are current enough to deal with any issues that might arise.
Lastly, be prepared to end the dive for any reason...you can always come back another day. The “thumbs up” signal does not mean go up, it signals to end the dive, and we should always feel that we can use it in any circumstance, and not be required to justify why we have done so.
Enjoy your return to the underwater world!