Nav speciality: report

[Zept]

My buddy and I completed the PADI Navigation speciality on Sunday. I wanted to dive locally, but the viz around Singapore is rubbish (typically around 1m/3ft), so we figured we'd learn something.

On the first dive we measured the number of kick cycles required to cover 30m. I get 35, she gets 17. Huh? My excuse is that I was doing small kicks to avoid stirring up the bottom.

The next exercise is hexagons. She navigates the first one, making 60-degree turns to the left. No problem. I navigate the second one, and I figure I'll turn to the right. On the second leg I run into the reef, which goes up to within 2m/6ft of the surface. Oops. If there's one thing I'm good at, it's finding the shallow spots... last time we dived at this location, we ended up in 1m of water. This time we just go back down and I start my hexagon again, turning to the left. Somewhere in the third or fourth leg, my mask floods and I realise I can't read the compass. While I'm clearing my mask, I lose count of my kick cycles, so I'm not surprised when I miss the starting point by 2-3m/6-9ft.

We also tried some natural navigation along the reef, and then finished the dive on a pile of rocks called Shark Rocks. When we surfaced, we triangulated our position.

For the second dive, our instructor laid out a course of six markers, then gave us a list of bearings and distances. Ha ha, we think, this'll never work.

I navigate the first leg and we plow straight over marker 1. Our instructor sorts us out and we head off for marker 2. This time we see the marker... but it's marker 3. Oops. My buddy figures out that she can find marker 2 using a reciprocal heading. Cool. Except I'm looking the wrong way and I get left behind in a cloud of silt. I hover for a few seconds, hoping it will clear, and then the others come back for me. We find marker 2, we find marker 3 again, and then it's my turn to navigate to marker 4. We swim straight up to it. Hurrah! I'm estimating fewer kick cycles per metre now, and my new figure seems more accurate.

We find markers 5 and 6, and then turn round to go back to the beginning. On the way from marker 5 to marker 4, I forget that I'm supposed to be using a reciprocal bearing and go 10m/30ft in the wrong direction. I'm thoroughly annoyed, but I turn round, go 20m in the right direction and swim straight up to marker 4. It's rapidly becoming my favourite marker.

We finish the course and surface, then attempt to drop back on to Shark Rocks, using the bearings from the first dive. One silt-covered rock looks much like another to me, but our instructor thinks we're in the right place. No sharks, of course, but we find a small remora. It thinks we're fabulous. It gets in my face, it tries to attach itself to my neck, it gets inside my BC, it wiggles round my arm... it is the World's Most Annoying Fish. I end up swimming along with my hands around my neck, yelling abuse at it. Grr!

Overall, the course was a lot of fun. I'm still kind of hazy about the east-west thing, but I'm much better at holding a bearing and estimating distance. And we got wet, which is always good.

Zept

 

[otter-cat]

That was a good report, Zept. The class sounds like a lot of fun. I hope to take it someday, along with nitrox, altitude, deep, cavern, ppb, etc.


otter-cat

 

[Jonathan]

I really am going to have to get the manual out again.... I didn't actually know there was such a speciality, makes sense though and there are a few instructors I know who could do with attending class....

Sounds like fun

Jonathan

 

[ymy]

I did nav as part of my AOW. The trouble I had was correcting for currents.

One tip I picked up was to pick a "land mark" along your intended bearing and swim toward that ... then pick another one etc etc. This helps with currents etc. Also it lets you look around instead of staring at your compass all the time.

Of course this won't work in low vis or if all you have is sand

 

[Zept]

The nav dive in AOW counts as the first dive of the nav speciality. That's why we only had to do two dives on Sunday, rather than three -- we'd already done the first one.

The advantage of doing nav in low vis is that you don't mind looking at your compass all the time .

Zept

 

[ymy]

I didn't realise specialties in AOW are different from taking specialties independently

Could you share what extra you learnt doing the specialty independently ... how about for the mandatory AOW ones, i.e. deep and night

 

[Zept]

To be honest, we didn't learn many new things -- mostly we refined the skills from the AOW dive. Navigating around the markers was more challenging than navigating around a square or a hexagon, because we had to work out how many kick cycles were required to go the specified distance, and there wasn't much margin for error. By the end I was kicking a lot more consistently and finding it easier to stay on course.

One new skill was triangulation. We came up from Shark Rocks at the end of the first dive, then took bearings from three surrounding objects. On the second dive we used the bearings to find the same spot and drop back on to the rocks.

The nav course was good for us because mostly we do drift dives in clear water where we can just follow the reef, so we don't use our compasses much -- and then when we dive in Singapore, we get lost. OTOH, if you're using your compass all the time, you might not need the practice. Likewise, I'm not sure I'd bother with the multilevel speciality, because I use the Wheel regularly and feel pretty confident with it, but I'd like to do the search and recovery speciality, because so far all I've done is pick up odd bits of litter.

The PADI Web site has info about all the specialities, although it's vague about the specific skills in each course. It's probably better to talk to your instructor.

Hope that helps,

Zept

 

[Jonathan]

In AOW you get a taster of 5 different specialities. I am not aware of any speciality course that requires less than 2 dives as that would kind of negate the need as everyone would do it as a AOW dive.......

For a lot of the specialities you use the AOW book - or at least you did a few years back which is why they might look like the same thing.

Jonathan

 

[ymy]

But are there any specifics you learn in the second or third dive ... or is it just the additional experience of more dives. Do you do more theory ?

As an example, for deep diving ... what additional does one learn doing a deep diving specialty as opposed to the AOW.

Maybe I should stay on topic and use nav as the example. For my AOW we actually did 2 nav dives. The first running a straight reciprocal course and the second a square. What more would I get out of taking the nav specialty ?

Not trying to challenge the specialties. Just want to know what I am missing.

 

[Zept]

ymy, I thought I'd answered your question in the post headed 'Extra skills'. Is it not showing up?

AFAIK, there are specific skills for the additional dives in the speciality courses. I believe there is additional theory work for some courses, but we didn't do any extra reading for nav -- just more briefings and more dives. Some specialities involve two dives, some three and some four (and in most cases, you can count your AOW dive as the first one). Some specialities have prerequisites -- you have to do either AOW or the nav speciality before you can do the search and rescue speciality, for example. In other words, the courses vary quite a lot.

A lot of people diss the specialities, but I think it depends on your level of experience, your instructor, your expectations, your location, and probably a bunch of other things. My nav course was cheap and I enjoyed it... seems good enough to me.

Zept