New computer, which Algorithm

[Dnaber]

Not sure if this would be the best place to ask this but as this pertains to safety why not ask the doctors. I'm getting a new Oceanic Pro Plus 3 computer next month. This new computer has two algorithm options, DSAT or Z+ (Petagic Z+) (which is based on the Buhlmann ZHL-16c). Of these two which would provide me with the best margin of safety as a new diver? Thanks

 

[tbone1004]

they will both provide you with sufficient margin of safety as you aren't doing decompression. Neither is better, they're just different. Most prefer Z+ as DSAT is pretty outdated in my opinion, based on the PADI tables which are the most liberal of the standard dive tables for repetitive diving.

Neither is more or less conservative across the board, the difference is in where the conservatism is rooted.

Z+ is more liberal on single deep dives, but more conservative on shallow ones, the DSAT is more conservative on the deeper stuff but generally more liberal on repetitive dives. So if you're doing standard recreational profiles, multiple dives a day all shallow etc, Z+ is probably more conservative, but if you are doing one or two deep dives per day, the DSAT is more conservative. Take surface intervals into account and the Z+ works better with long surface intervals, DSAT works better for divers wanting to maximize bottom time on quick turnarounds. Make sense?

For me if I had to choose, I'd use Z+ for most of my diving, which is one longish deepish dive in the morning, have a 2-3 hour SIT, then one in the afternoon. Deepish/longish is about 90minutes at 100ft. This would give me shorter decompression obligations than DSAT.
For reef type diving, quarry diving, etc where it is up and down up and down, short 30-40 minute dives at 30-50ft with 1 hour intervals, then DSAT would give me more bottom time and less deco than Z+. If you were trained with PADI tables and are using them to check the computer, then use DSAT as it will best replicate the tables.

Simply Scuba Blog » Oceanic Dual Algorithm

 

[Subcooled]

margin of safety as a new diver

Sorry, but this is not an algorithm issue really (although you got a great answer above)

If you want to be conservative, then you could always end the dive well before the NDL timer hits zero, stay a minute extra at 6m/18ft (safety)stop, ascend very slowly to the surface, rest after the dive (not carry tanks), avoid coffee and alcohol during dive trips, dive with nitrox following air tables, drink plenty of water and stay hydrated, sleep well, keep yourself in better physical shape, add longer surface intervals and resting days and avoid the fourth dive of the day... I would guess that these procedures would have more effect than the slight differences in algorithms.

 

[Dr Deco]

Hi Dnaber:

Tables and computers are conservative for recreational diving. They vary somewhat according to the designer's preferences. The PADI table was laboratory and open-water tested with recreational divers. Basically, however, watch your physical activity post dive as this can increase the DCS risk level. For example, do not carry air tanks uphill, etc.

 

[Scubanoobi]

DSAT will give you longer NDLs in the recreational depths, but if you happen to go into deco you will probably run out of air before the deco clears.

Z+ will give you less time at rec depths but if you happen to go into deco it seems to give more realistic deco stops.

DSAT will give you 57 minutes at 60 feet vs 48 minutes on Z+.

Both are safe.