sports diver exam question.

[sharkbait]

I did my sports diver exam a couple of months back, and whilst I enjoyed learning to at last use tables that included decompression diving, I was gob smacked by the question I got concerning repetative dives with flying and travelling over Ben Nevis size mountains on the way home.
1) The question seems un-neccessary as only a complete loon would contemplate doing the dives.
2) Its way too complicated. Neither of my instructors could get it right. Nor at first my buddy an Engineer and myself a Physicist.
3) I eventually figured it out after seeing the answer, but wouldn't trust myself to base my dive planning on the chance that I think I know what I'm doing with the tables.
4) Disregarding a dive holiday in La Paz, Is it really likely you will be driving over a 1000m mountain in the UK? (There are only 80 or so mountains in Scotland over 3000 foot.)
5) I have now forgotten how to do the question and I reckon that few of you that got it right (without guessing) can still remember how to do it.

Wouldn't it be better to concentrate on the basic table stuff instead? Frankly I thought it a waste of a question.

[Dave]

I did my sports diver exam a couple of months back, and whilst I enjoyed learning to at last use tables that included decompression diving, I was gob smacked by the question I got concerning repetative dives with flying and travelling over Ben Nevis size mountains on the way home.
1) The question seems un-neccessary as only a complete loon would contemplate doing the dives.
2) Its way too complicated. Neither of my instructors could get it right. Nor at first my buddy an Engineer and myself a Physicist.
3) I eventually figured it out after seeing the answer, but wouldn't trust myself to base my dive planning on the chance that I think I know what I'm doing with the tables.
4) Disregarding a dive holiday in La Paz, Is it really likely you will be driving over a 1000m mountain in the UK? (There are only 80 or so mountains in Scotland over 3000 foot.)
5) I have now forgotten how to do the question and I reckon that few of you that got it right (without guessing) can still remember how to do it.

Wouldn't it be better to concentrate on the basic table stuff instead? Frankly I thought it a waste of a question.

If taught properly, the tables questions are the trivial ones on the exam paper and should be guaranteed marks. Since altitude diving / travelling at altitude are incorporated in the tables then it is quite reasonable to include them in the exam. Do remember that the world does consist of areas outside the UK; some of us live overseas

The travelling et al issues are quite trivial and each possibility is explained on pages 5-8 of the BSAC 88 tables booklet. If you refer to that during the exam , then you should have no issues

In an example of driving over a mountain, this is coveredin example 7 of the table

(1) calculate the SC from the 1st dive; let's assume that it is B for an example

(2) Go to the Altitude/Pressure chart on Page 30 and see what level the altitude being travelled to is ( in your example, Level 3 )

(3) Use the transfer Table on page 29 and B/1 becomes D/3

(4) Since the journey over the mountain is at unknown varing altitudes during the journey, no off gassing is allowed for ( again explained in example 7 ) so you then transfer from D/3 to C/1

(5) Calculate your next dive based on being at CTC of C

Dave

[David Walker]

Wouldn't it be better to concentrate on the basic table stuff instead? Frankly I thought it a waste of a question.

If you dive on tables then its relevant. Diving in the lake district and places like that can easily get you into that kind of table work. OK the example in the question may be a bit extreme if it is talking about going so high, but the principles of it are exactly the same as for a transition from level 1 to level 2. It should be something easy enough to do if you know all the rules that the tables follow (and complete instructions of how to use them, with examples, are actually included in the front of the tables). Generally the questions that people (everyone!) don't 'get' are ones where the question is badly worded or simply misprinted (which is a LOT of questions if you haven't updated them all - there's an erratta section on the main website somewhere, although frankly by now a corrected version of all papers should have been made available to clubs / instructors!).
If you point us to the exact question then it may be a misprint somewhere. If not, then I don't remember any 'tables' questions in any of the papers that are particularly difficult to solve - its just a case of following the rules of the tables.

All of that said, I don't know anyone who's ever used them for real diving, since to be honest I don't know of anyone who dives on BSAC tables except on specific lessons where they're required to. Does that make the more advanced table stuff irrelevant? No more so than the tables themselves, but we can't really get rid of them in which case for those who do use the tables they *should* do the calculations if they're diving somewhere up in the hills.

David

[Dave Woodward]

There's a BSAC Ice Diving Course being run in the Austrian/Germany Alpine area, open to Sports Divers next month, some people will be flying out to it, others like me will be driving from Switzerland. Out this way there is often scope for changing altitude at short notice.
I dive in Lake Geneva, however, I may be diving in Annecy, and drive back along the motorway that goes up quite a bit before dropping down, or I may want to head up to Chamonix

Back in the UK, we used to drive up to the west coast, of Scotland. Not sure of the altitude, but the road back from Oban to Glasgow goes halfway up a mountain. Bear in mind, we are looking at the pressure on the day as well, which can make a big difference to what group you are one. Not sure of the details, but I heard one of our lot got a bend on the way back from Oban recently.

Dave


I did my sports diver exam a couple of months back, and whilst I enjoyed learning to at last use tables that included decompression diving, I was gob smacked by the question I got concerning repetative dives with flying and travelling over Ben Nevis size mountains on the way home.
1) The question seems un-neccessary as only a complete loon would contemplate doing the dives.
2) Its way too complicated. Neither of my instructors could get it right. Nor at first my buddy an Engineer and myself a Physicist.
3) I eventually figured it out after seeing the answer, but wouldn't trust myself to base my dive planning on the chance that I think I know what I'm doing with the tables.
4) Disregarding a dive holiday in La Paz, Is it really likely you will be driving over a 1000m mountain in the UK? (There are only 80 or so mountains in Scotland over 3000 foot.)
5) I have now forgotten how to do the question and I reckon that few of you that got it right (without guessing) can still remember how to do it.

Wouldn't it be better to concentrate on the basic table stuff instead? Frankly I thought it a waste of a question.

[Gary Cameron]

Wouldn't it be better to concentrate on the basic table stuff instead? Frankly I thought it a waste of a question.

I reality i think the oppisite is appropriate. Our Club dive at the Lake district quite often and the tables are very useful for planning return trips over the hills. Especially if diving in lakes with altitude. Wastwater is deep and particular attention must be paid to altitude on the way to and home.

I would also go as far as saying the most people dive on computers and still use the tables for multi-level multi dive planning.

Regards

Gary Cameron
York BSAC

[nick kay]

Lets add some real-world observations:

1. Stoney Cove on a "low pressure" day is a Level-2 dive
2. You dive on the Western side of the M62 (maybe you're only doing The Delph or Capernwray), and drive home back across to the Eastern side - you pass over a point on the M62 that's at 273m
3. You go for a diving trip to Oban - you should come back the western/coastal route. If you come back the eastern route, its another altitude return

OK, none of these are 1000m (not sure about the Oban example), but they all illustrate the point that there are situations where you should factor in the travel.

Again, with regards to flying after diving... Hopefully everyone returns to (at least Table B) before flying... The questions are undoubtedly to check you understand how to do the calculations but also reinforce that you understand the implications / consequences if you don't follow the guidance...

[Philip Smith]

3. You go for a diving trip to Oban - you should come back the western/coastal route. If you come back the eastern route, its another altitude return

OK, none of these are 1000m (not sure about the Oban example),

High points on the road from Oban:
Nr. Tyndrum (A85), 273 m
Rest and Be Thankful (A83), 246 m

Others:
Rannoch summit (A82), 348 m
Pass of Drumochter (A9), 424 m

Phil S

[steve swift]

Lets add some real-world observations:

1. Stoney Cove on a "low pressure" day is a Level-2 dive

Is that really true???? If so you'd have thought that Stoney would put something up to that effect. How bad a day does it have to be?
When I am at Stoney, I am virtually always on Tables as I will be doing training - and that often involves several dives and multiple ascents. If the location is potentialy at Level 2 it will have some serious implications on dive planning.

Steve

[Dave]

:=Lets add some real-world observations:
:=
:=1. Stoney Cove on a "low pressure" day is a Level-2 dive

Is that really true???? If so you'd have thought that Stoney would put something up to that effect. How bad a day does it have to be?
When I am at Stoney, I am virtually always on Tables as I will be doing training - and that often involves several dives and multiple ascents. If the location is potentialy at Level 2 it will have some serious implications on dive planning.

The Altitude of Stoney Stanton is 77m/255ft . If the barometric pressure is below about 995mB then you should be on Level 2 tables

Dave

[steve swift]

The Altitude of Stoney Stanton is 77m/255ft . If the barometric pressure is below about 995mB then you should be on Level 2 tables

Dave

Sheeesh! I'm glad I was trawling through this thread. Perhaps Stoney should put the pressure up on their conditions blackboard. I will certainly be taking a closer interest in pressure if I am going there on bad weather day - on second thoughts, perhaps this would be a good excuse not to have to go!!

Thanks
Steve

[Annie]

Perhaps Stoney should put the pressure up on their conditions blackboard.

Stoney Cove used to put altitude on the board, and atmospheric pressure on the weather chart in the shop. Don't they do it any more?

It is my standard first question when taking SD trainees in Stoney "What table are we on?", then let them find the info, and work it out.

Oh, confession time! Going back to the original post, I once dived the Zenobia in the morning and then drove up the Troodos Mountains (1900 metres) in the afternoon. Possibly not the wisest move of my diving career!

Annie

[Nigel Hewitt]

Oh, confession time! Going back to the original post, I once dived the Zenobia in the morning and then drove up the Troodos Mountains (1900 metres) in the afternoon. Possibly not the wisest move of my diving career!

My son and I did a DDRC pot dive and, since Plymouth is a long way and we didn't need any kit, we flew down. It seemed a good idea until the intro session when the guy said "Of course none of you are planning on flying in the next 24 hours..." and we had a small aircraft sitting at the airport.

*bangs head*

So we chugged back low level.

nigelH