You would be in Pressure Group F.
Improved AnswerUsing which table and which depth? ... since 12 meters is not 42 feet and instead is 39.4 feet. Using PADI's RDP, you have a PG of D if using the metric table of 12 meters or the imperial table of 40 feet. If using 42 feet on the table version of the RDP, then the PG is F, but if using the wheel or the new electronic RDP, then the PG is E (as it rounds up to 45 feet).
With the U.S. Navy table (or a modification thereof such as NAUI's or SSI's version), then the PG is C at 12 m./40 ft.
The BS-AC' 88 table gives you a PG of C and the DCIEM table results in B.
According to NAUI's dive tables: 25 Minutes 17 Meters for 23 minutes: Group E 30 Minutes at surface: Still Group E (Would need 55 minutes to go to D) 25 Minutes is your adjusted maximum dive time for up to 18 meters.
Pressure group F.
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00:04 ~your welcome :/
00:04 ~your welcome :/
The no-decompression limit at 18 meters is 48 minutes and that will take you to pressure group S. This information can be found in any Table or wheel RDP (recreational diving planner) and it is basic. If you do not know how to use this table, you shouldn't really be diving. If you are in a course, then you will have a lot of time to practice. Dont forget to dive well within your no decompression limit. Live on the edge, Dive safe.
To experience a pressure of 2 ATM, you would need to dive to a depth of 20 meters (2 ATM = 1 ATM (surface) + 1 ATM (pressure at 10 meters depth)). At a depth of 100 meters, the pressure would be approximately 11 ATM (1 ATM at surface + 1 ATM for every 10 meters).
The deepest dive to the bottom of Atlantic ocean was 10,994 meters deep. It was done by Don Walsh in a submarine and the dive took 4 hours and 47 minutes.
the pressure is more than the human body is designed to cope with.
Of course it depends on the depth, but the maximum is 219 minutes at 10.5 meters.
The final pressure group you would be in is M.
Narwhals have been recorded diving to depths of 800 to 1,500 meters (2,600 to 4,900 feet) while foraging for food, typically staying submerged for about 25 minutes per dive. Their long, spiral tusks are thought to aid in breaking through thick ice to reach their prey.