10  m

20  m

30  m

30  m

40m

100  m

6  m

10  m

10  m

10  m

30  m

60  m

N/A

N/A

N/A

N/A

30 min

As Req’red

N/A

N/A

N/A

N/A

1.6 pO₂

1.6 pO2

1.45 pO₂

1.45 pO₂

1.45 pO₂

1.45 pO₂

1.45 pO₂

1.45 pO₂

3.2 pN₂

3.2 pN₂

3.6 pN₂

3.6 pN₂

3.6 pN₂

3.6 pN₂

2 Hrs

8 Hrs + 1 pool dive

16 Hrs

16 Hrs

16 Hrs

30 Hrs²

1*

2*

2 pool dives 4-6*

2 pool dives 6-8* OW

4*

6-10 ³

optional

120 min

120 min

180 min

optional

optional

30 min

100 min

180 min

300 min

120 min

120 min

N/A

N/A

N/A

N/A

180 min

240 min

OW certified

OWD + LSU + 10 prior OW dives

CSU + 20 dives or AOW

OWD+CSU* +50 prior OW dives

SCR /CCR +TSD+ pretest + 25 rebrther dives

TRD +200 prior OW dives+ 50 rebrther dives

1 - includes CSU lectures.     
2 - includes ERD & CCR and TMD lectures.
3 - All rebreather courses are unit specific - times or dives may vary.  
4 - CCR only.
* - see the instructor procedures for the specifics for the dives ..... other prereq's may apply

TRD with Normoxic Trimix (TTR) is possible as well . Ask your instructor for the details