Uwatec Smart COM question - microbubbles and deco

[Alucard]

Thanks for everyone for your help. First a couple of comments:

Drinking and diving - no thanks.

The MB level was explained to me by my instructor as: Assuming you do not have heart condition or any sort, you should start your diving at L0. If you are doing multiple dives over multiple days, each day ramp up your MB level by one. When you get to 5 you probably should take a day off diving anyway.

As for the comment about using a computer for a beginner - a couple of comments of mine:

First, where we certified they were doing boat dives where computers are MANDATORY - wasn't an option for us. However, during my SSI certification we used the tables, went through a lot of exercises and am comfrtable using them if necessary,

Second, I don't try to figure out my computer while diving. I try to figure it out when I an NOT diving I have found it extremely easy to use and it has allowed me to concentrate on my diving skills like bouyancy, etc.

OK, here's my supplementary question about the MB level. I do not want to be diving and suddenly go into needing deco stops. I do not mind doing level stops because of the MB level, though, and am ok planning those into the dive.

So if the DC is showing level stops, and I want to know how long I can still go without needing a deco stop, how do I find out? It's not at all clear for me, either from using the computer, reasing the manual or looking online. (Note, I do NOT want to even get CLOSE to the deco stop limit - I just want the peace of mind of knowing how long I still have.

hanks to everyone so far for your views.

 

[HowardE]

The MB level was explained to me by my instructor as: Assuming you do not have heart condition or any sort, you should start your diving at L0. If you are doing multiple dives over multiple days, each day ramp up your MB level by one. When you get to 5 you probably should take a day off diving anyway.

This is rediculous - your instructor is doing you a dis-service by telling you that.

OK, here's my supplementary question about the MB level. I do not want to be diving and suddenly go into needing deco stops. I do not mind doing level stops because of the MB level, though, and am ok planning those into the dive.

So if the DC is showing level stops, and I want to know how long I can still go without needing a deco stop, how do I find out? It's not at all clear for me, either from using the computer, reasing the manual or looking online. (Note, I do NOT want to even get CLOSE to the deco stop limit - I just want the peace of mind of knowing how long I still have.

The real way to know you're not going to go into deco, is to KNOW and USE the dive tables.

Do you know how to use the dive planner mode on your dive computer? You can compare the same profile from L0 - L5 and you'll see the difference.

The thing is - your computer will not just give you 10 minutes of DECO - it will start at 1 minute of DECO. So if you're just diving your computer, then once you hit 1 minute of DECO - GO UP. By the time you get to 15' - you'll probably be clear of the Deco Stop anyway.

 

[Alucard]

This is rediculous - your instructor is doing you a dis-service by telling you that.

Really? It seems to mirror quite well the advice given in the instruction manual for the computer, too.

The real way to know you're not going to go into deco, is to KNOW and USE the dive tables.

Which assumes a square profile which I rarely, if ever, dive. Not knowing the dive sites I do not know what sort of profile I am going to be diving, right? It sounds like what you are advising is that I take the tables underwater with me and stop every so often and calculate my deco time, yes? Please correct me if I am wrong, because I'm not sure what you sre advising here....

Do you know how to use the dive planner mode on your dive computer? You can compare the same profile from L0 - L5 and you'll see the difference.

Yes, I do know how to use the planner - it also assumes a square dive profile. I have seen the various graphs that others have made about how the MB level affects the level stops.

The thing is - your computer will not just give you 10 minutes of DECO - it will start at 1 minute of DECO. So if you're just diving your computer, then once you hit 1 minute of DECO - GO UP. By the time you get to 15' - you'll probably be clear of the Deco Stop anyway.

Right, but I guess what I would likie to do is to know while I am underwater how long until that 1 minutes is going to kick in (which I can see if I am L0 on the MB) - that way I can make sure I am going to be close to the boat so I don't have to do a long surface swim once I come up.

Look, I can fully appreciate the idea of people who advise using tables to get your initial experience, and I respect that - I can understand that it gives a good, fundamental pratice as to good diving practices, but it's just not feasible on some of the Caribbean boat dive operations - they insist on using the computer.

I will, however, mimic what I am doing with the tables, so I have more expereince of using them, though. Sorry if my question about trying to understand my dive computer annoyts some people because I am such a noob.

 

[mark99]

You are correct, there is no way to tell how much actual (L0) NDL time you have left when you are set in L1-L5. You see how much time before your first required level stop, after you start seeing level stops, there is no indicator for how much (more) time you have before the actual NDL. I have used another dive computer simultaneously with the Smart-Tec (wrist version) to see how much (approx) NDL time is left. This is obviously not the best solution, since the two computers could possibly give different NDL times.

 

[HowardE]

Really? It seems to mirror quite well the advice given in the instruction manual for the computer, too.

Really? I did 8 dives in the last 3 days, all on L1. Some deep. You should be able to leave it on L0. If you want to do level stops - on your computer - set it to L1. There's no reason (unless you have a medical condition to) do L5. I don't see where the book suggests that you use L5.

Which assumes a square profile which I rarely, if ever, dive. Not knowing the dive sites I do not know what sort of profile I am going to be diving, right? It sounds like what you are advising is that I take the tables underwater with me and stop every so often and calculate my deco time, yes? Please correct me if I am wrong, because I'm not sure what you sre advising here....

You should use the wheel then.

I look at the time for my deepest depth. If I'm doing a drift dive, and the ocean floor is at approx 60'... I make sure that I'm good for at least 60 minutes at 60' before I do my second dive. Sure it may be multilevel, but at least I know I can do the hour I want.

I will, however, mimic what I am doing with the tables, so I have more expereince of using them, though. Sorry if my question about trying to understand my dive computer annoyts some people because I am such a noob.

Not annoyed at all... If I was - I wouldn't have tried to help you

But so you know... I have used my smartcom for 186 dives. I have done as many as 25 dives in a 5 day period with it, and have never raised it higher than L1.

 

[Dibblerr]

Really? It seems to mirror quite well the advice given in the instruction manual for the computer, too.

Everyone has an opinion of what makes for a safer dive, Take in the information you hear and decide for yourself what you want to do, The only 'guaranteed safe' way to dive is to stay out of the water

Right, but I guess what I would likie to do is to know while I am underwater how long until that 1 minutes is going to kick in (which I can see if I am L0 on the MB) - that way I can make sure I am going to be close to the boat so I don't have to do a long surface swim once I come up.

Assuming you follow the computers advice you will be doing level stops, these will ultimately put you in 3M(10ft) of water, as far as I am aware it is impossible to get into deco in 3M of water
If you want to to stretch your time beyond that then you are not using the conservatism of the L1-L5 feature and shouldnt be in that mode in the 1st place, you have to decide whether you are following the computer or not, you cant have it both ways