Blindly trust computers?

[BRT]

Does that strategy make... sense...to you?

Are you one of the geniuses that can calculate your N level on the fly while changing depths? If not, it was the only strategy available before dive computers. Unless you were going to spend certain times at certain depths and do a true multilevel dive.

 

[BRT]

Is this really going to be beaten to death... again?

Waste of time.

 

[jlcnuke]

I think the real bad idea is Open Water divers that have no clue how to plan a dive and are unaware when their magic box spits out baloney.

The vast majority of OW rec divers dive infrequently. Most, taught tables or not, would need a refresher class before any vacation where they are going to dive, if they wanted to remember how to use tables anyway. They're going to go to Cozumel/Bahamas/etc etc and dive with a boat. That boat is going to take them to a spot that the boat knows, with depths the boat knows, and tell them to be back in an hour, and the divers will suck down their air in 45 minutes and surface with 30+ minutes left on their NDL.

That diver is NOT going to go take a dive theory course annually so they can have a reasonable chance of determining if the computer their diving, and their dive buddies computer, are full of crap. And for most of their guided, very conservative diving experiences, that's just fine. The tiny percentage of rec divers that DO dive regularly likely have a good idea if their computer is way off base just from experience. They don't need a course to tell them that the computer saying they have 45 minutes til they hit their NDL at 130 ft on air is not functioning properly.

 

[yle]

Cough *average depth* cough

Using average depth can get you into trouble. It would only work effectively if NDL is a linear function of depth... which it's not. To see why, consider that the NDL for 70 feet is 40 minutes, while the NDL for 110 feet is only 16 minutes (I'm looking at the PADI RDP table.) I could spend 36 minutes at 70 feet be well within my NDL, but spending 18 minutes at 110 feet and another 18 minutes at 30 feet puts me into deco. Both scenarios have the same time-averaged depth.

Admittedly, understanding the definition of a function, the average value of a function, and the practical limitations of these definitions is not basic math. But it's important math for situations like this.

 

[Ryan Mcshane]

Wut?! Run those numbers and tell me what the deco is? ... *pssst it’s none.

Using average depth can get you into trouble. It would only work effectively if NDL is a linear function of depth... which it's not. To see why, consider that the NDL for 70 feet is 40 minutes, while the NDL for 110 feet is only 16 minutes (I'm looking at the PADI RDP table.) I could spend 36 minutes at 70 feet be well within my NDL, but spending 18 minutes at 110 feet and another 18 minutes at 30 feet puts me into deco. Both scenarios have the same time-averaged depth.

Admittedly, understanding the definition of a function, the average value of a function, and the practical limitations of these definitions is not basic math. But it's important math for situations like this.

un th

 

[PfcAJ]

Using average depth can get you into trouble. It would only work effectively if NDL is a linear function of depth... which it's not. To see why, consider that the NDL for 70 feet is 40 minutes, while the NDL for 110 feet is only 16 minutes (I'm looking at the PADI RDP table.) I could spend 36 minutes at 70 feet be well within my NDL, but spending 18 minutes at 110 feet and another 18 minutes at 30 feet puts me into deco. Both scenarios have the same time-averaged depth.

Admittedly, understanding the definition of a function, the average value of a function, and the practical limitations of these definitions is not basic math. But it's important math for situations like this.

Does it?

Imgur

You’re within bounds if you don’t spend those extra 2 mins at 110’.

 

[yle]

The vast majority of OW rec divers dive infrequently. Most, taught tables or not, would need a refresher class before any vacation where they are going to dive, if they wanted to remember how to use tables anyway.

I'm going to respectfully disagree with your last statement here. If an OW student was taught how to use the tables properly, they shouldn't need to a "refresher class" before any vacation. They should be able to review it themselves to refresh their own memory. It would take maybe a few minutes. If they're truly interested in being an informed and safe diver, they would make reviewing tables for a few minutes a part of their prep for any dive vacation.

And of course I'm sure they could ask a few questions of their dive guide if they needed to. I would imagine any dive guide at a tourist destination would be overjoyed to have one of their guests interested enough to ask questions about dive tables.

 

[lexvil]

Suunto settles scary scuba screwup for $50m: 'Faulty' dive computer hardware and software put explorers in peril

Some folks on SB keep advocating for understanding decompression and gas/time relationship using the simplest tools possible (tables, pre-dive planning, methods to monitor actual gas usage vs expected gas usage). Computers can be helpful, but over-reliance can compromise your safety and abilities as a diver.

Not to interfere with the outrage but the point of the suit is that the makers “knew” of the issue and didn’t fix it and passed off likely faulty equipment, “knowingly” in answer to a known fault. I assume the suit was brought in Ca. because the HQ of aqualung is in Ca.

A $50 million settlement isn’t agreed to easily by any manufacturer unless the liability is much higher. I’m glad the suit was brought in a State that often values consumers over corporations.

 

[yle]

Does it?

Imgur

You’re within bounds if you don’t spend those extra 2 mins at 110’.

My point was to create an example of two dives with the same average depth and the same time which do not give the same NDL result. That is, an example to demonstrate that NDL is not a linear function of depth.

 

[yle]

I assume the suit was brought in Ca. because the HQ of aqualung is in Ca.

I'm going to suggest that was just coincidence. AL was only a distributor for Suunto (i.e. AL has no ownership in Suunto), and they gave that up a couple years ago (maybe three?) Huish, which owns Atomic, Bare, and collection of other scuba companies, has been the US distributor for Suunto for the past 2 or 3 years.

The suit was likely filed in California because the plaintiff lives in California... as do a lot of other divers.