Search and Recovery Diving
We’ve all been there, or know someone who has. You’re leaning over the edge of the boat (maybe in an effort to catch a glimpse of the whale that everyone else saw), then you hear the inevitable ‘plop!’ as your expensive sunnies drop into the deep, dark abyss of the ocean. Gone forever as the current takes your Ray Bans on an exclusive tour along the bottom of the sea floor. Or, maybe not gone forever if you’ve done your course!
After learning about underwater navigation and dive patterns, we put our newfound skills to use in the form of recovering some novel objects (think tiny toy Smurfs and other random bits and pieces!). It was a great way to practise navigation skills and underwater communication with our buddies. Our dive master hid some objects and we used two techniques to find the items – U search and expanding square. A U search involves starting in one corner of the search area, swimming a straight line for a certain distance (remembering your kick cycles from the navigation training), turning 90 degrees and swimming for a short length, then turning 90 degrees and swimming back that same distance. Repeat this until you cover off the search area. A compass is critical for this kind of search! An expanding square search is pretty straight-forward too. Start in the centre of the search area and swim a short distance (this will depend on visibility), make a 90 degree turn, swim a slightly longer distance, make another 90 degree turn, swim longer again and keep doing this until you cover the search area.
We found all the Smurfs using these techniques and even managed to find an object that another dive company must have been using to train their students. We took it back with us because, as the mantra goes, leave nothing but bubbles!
While we utilised navigation skills learnt on our previous dive, there were still some new skills we were tested on. This made for a slightly stressful lunch break, frantically learning how to tie various knots – if you want to relax while you down your hot soup, I’d recommend learning these knots before you come to the course. They’re in your manual, so no excuses!
Why were we tying knots, you ask? Well, it’s all well and good to find teeny tiny figurines underwater, but in the event you’re looking for something heavier, you’re going to need to utilise a lift bag to bring the object to the surface. As a general rule, use a lift bag for objects weighing more than four kilograms. NEVER use your BCD to help lift an object, because if you drop it as you ascend, you risk a dangerous runaway ascent. Of course, to tie an object to a lift bag, you need to know how to tie a variety of knots. And because none of us were ever Scouts, and none of us had thought to practise these knots prior to the course, we all spent our break between dives learning how to tie a bowline, sheet bend, and two half hitches (knowing that it would probably be harder underwater!).
All in all, this was a good module to complete because we now have some really useful skills under our weight belts (ok, that was a bad pun). And who knows? Maybe you could utilise these skills to .
What’s the strangest thing you’ve found (intentionally or unintentionally) underwater?