Do you know where you are going? – Underwater Navigator

suunto compassI’ve been using compasses to navigate since I was 12 and I started doing the Duke of Edinburgh Award. So I am familiar in how they work, their limitations and how useful they can be.

I just completed my PADI Underwater Navigator Speciality. This course normally comprises of 3 dives. However, as I had completed my PADI Advanced Open Water Diver course this meant I had already done the first dive (this is because Underwater Navigation is a compulsory course for the AOW).

We were back at Ghar Lapsi for this course as the house reef was a little too rough. So we start with the first dive, I mean second dive, of this speciality. Howard, my instructor for these specialities, gave me a clear briefing on what we were doing. I was to mark on a slate points of interest for navigation and any compass bearings that I wanted to, while he swam around on a course. We would then finish the dive. At the end of the dive we would find a fixed marker underwater using 3-point-fix. A 3-point-fix is where you find 3 objects on land and take compass bearings of each of them. The idea is that where those bearings cross is where you are. The reality is that this is fairly accurate on land when you are stationary, but when using a diving compass and you are being jostled by waves makes for fairly inaccurate bearings. My only problem was the fact the I had just redistributed the weights about my BCD so I spent the first 5-10 minutes of the dive getting accustomed to that, see my previous post.

So once we had completed the second dive,  we then discussed the route that we had taken. For the third dive, I would be navigating the reverse journey.

I was quite excited about this as this is the first time that I have actually “led” a dive. We started by locating the fixed underwater marker using the three-point-fix. I could have looked down and found it but I tried hard not to and used the compass. When I thought I was over it, I said to Howard and he asked me to check. I was right above it. This filled me with confidence, we descended and started the navigation using the slate for reference. Everything went well until turn 12. I got a little lost and overshot my marker. However, I then found my way and we continued for the remaining 3 turns. PADI’s requirement is that you follow a course for a minimum of 5 different turns. My course had 15 different turns. So making 14 out of 15 turns wasn’t bad.

We then did our safety stop inside the cave system. There was a bit of swell so we had to be careful when exiting because we were getting sucked through the entrance.
I am pleased that I passed this course. I now feel more confident with my underwater navigation. If I was to change one thing is that I would put the reciprocal bearings on the slate so that I wouldn’t have to work them out while trying to navigate. I would like the opportunity to do a little more. Perhaps if I do the HMS Maori from the shore I can lead us to and from the site.

Tomorrow I should be doing Search and Recovery or Wreck. But secretly I want to do Drysuit or Sidemount.


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