Dive computer manual stating multiple dives per day for more than a week unsafe?

[Dave_lucas]

My dive buddy for an upcoming trip called me today and was reading the manual for his new Cressi Leonardo and it states in the manual.

-----------------------------------------------------
_ WARNING: Currently, no validated
scientific literature allows to dive more than
twice a day for periods of one or more weeks
without the risk of decompression sickness.
For your own safety, it is important to avoid
diving for more than two times a day.
----------------------------------------------------

I am a bit confused by this statement?

I frequently hear people talking about how many dives they have logged in a week or two while on a live aboard. Also looking at the dive tables it just does not compute?

It would be great to see some information to back this up or refute it.

 

[diversteve]

Their lawyers made them write that...

 

[doctormike]

My dive buddy for an upcoming trip called me today and was reading the manual for his new Cressi Leonardo and it states in the manual.

-----------------------------------------------------
_ WARNING: Currently, no validated
scientific literature allows to dive more than
twice a day for periods of one or more weeks
without the risk of decompression sickness.
For your own safety, it is important to avoid
diving for more than two times a day.
----------------------------------------------------

I am a bit confused by this statement?

I frequently hear people talking about how many dives they have logged in a week or two while on a live aboard. Also looking at the dive tables it just does not compute?

It would be great to see some information to back this up or refute it.

If it makes you feel any better, currently, no validated scientific literature allows a single dive without a risk of decompression sickness.

If you breathe compressed air underwater, you are at some risk for decompression sickness. The more dives you do and the less time between them, the greater that risk. Taking up the hobby of scuba diving is all about managing that risk, reducing it to an acceptable level for you, and drawing a bright line through a grey area.

 

[Mr Carcharodon]

There is validated literature and it applies to compartment pressure. Follow that and your risk will be low. You can dial that back even lower by making slow ascents and taking long safety stops and and having oxygen on hand for the few dives that go south. Sure you can find a dive plan that may not have been tested before but if you fall within the already well known allowables your risk is low. Something like 1:2000 low if you run up right to the limits. There is nothing at is zero risk including staying on the boat and not diving.

 

[KevinNM]

There are pretty smart people who suggest taking a day off if you have been diving multiple times a day for multiple days, like 1 day a week off. There are also some studies that seem to show protective effects of acclimatization by diving a lot. But Deep into Deco's survey of the literature suggests that there is no conclusive evidence either way, though there are theories that support both ideas.

 

[Doc]

-----------------------------------------------------
_ WARNING: Currently, no validated
scientific literature allows to dive more than
twice a day for periods of one or more weeks
without the risk of decompression sickness.
For your own safety, it is important to avoid
diving for more than two times a day.
----------------------------------------------------

I am a bit confused by this statement?

No.

What you're confused by
is that the computer continues to work,
even after the "violation" it warns you about.

Now that's a conundrum.

 

[MXGratefulDiver]

It's nonsense.

No liveaboard I've ever been on limits you to two dives per day. I doubt that one exists that would enforce that rule, as no one would ever choose to use it.

Typical liveaboard offers 3 to 4 dives per day for however many days you're onboard. I've yet to see anyone suffer the effects of DCS from multiple dives over multiple days.

A more practical consideration would be to limit your dive profiles and ascent rate ... and the more frequently you dive, the more important it becomes to choose conservative profiles and make slow ascents.

Nitrox comes in handy too ...

... Bob (Grateful Diver)

 

[RJP]

Typical liveaboard offers 3 to 4 dives per day for however many days you're onboard.

I'd stay away from any that only offered 3... why bother?

 

[100days-a-year]

Up to 7 dives a day for a week and totaling 24 days in one month.From 80' to 180' diving a mix of air or lean nitrox as we only carry 2 Ts of 02 and PP blend for 3-4 divers.No hits due to using shorter RTs.

In the Keys on vacation have had 30 days out of 31,3ish dives a day.1 deep @140' to 200' ...1 @60' to 100'...1-2 @ 15' to 30'

Either way up to 100 dives in a month at times,no hits.All about RTs and ascent rates.

Modern computers have to be designed around overweight,out of shape,hungover divers likely to have an undiagnosed PFO.Due to an overabundance of lawyers.

 

[Dave_lucas]

Thanks for the responses.

I do my best to be a safe diver and tend to error on the side of caution and was a bit taken back when presented with that information.

My first concern upon reading that information is that there were some safety concerns that I was not aware of and wanted to educate myself about the risk associated with multiple dives per day over an extended period of time. It sounds like the risks are unknown at this time but I am glad that it made me stop and think about the idea / theory… And post something for the first time instead of just lurking

2^nd concern was that we would get down there and the computer would limit us more than standard dive tables and at that is the exact opposite of what the computer is supposed to do.

Our plans seemed safe from looking at tables and what I have read but this will be the first time I have taken a trip that is mainly focused on diving so I never really put much thought into it as we normally dive a couple of days and then go do something else for a day or two and then back to diving again.

The trip in question will be to Grand Cayman @ cobalt coast and we plan to do mostly shore diving and at least one boat dive (kittiwake). Shore diving days 40 – 60 ft max depth slow assent to shallower water ~90 min SI (or longer if required by computer). We dive single tanks on air. Kittiwake is @ ~60 ft. I am sure there will be a day or two in there where we do not dive or only do one shore dive.

No.

What you're confused by
is that the computer continues to work,
even after the "violation" it warns you about.

Now that's a conundrum.

I know people hate on the Leonardo for beingconservative but I can not imagine anyone would ever buy one if it limited youto two dives per day. I figured it was more of a CYA situation on the company’sbehalf.