Perdix 2 - Minimum Surface Interval

[Ross19966]

I can figure this out by looking at the dive tables, but I'm thinking the Perdix 2 should display this info while in surface mode. I know it tracks surface interval but I don't see any mention of displaying minimum surface interval in the manual. Like if I dive to 60ft for 40 minutes, will the Perdix 2 tell me how long I need to be on the surface before another dive?

 

[RobPNW]

Does the surface interval depend on your intentions for the second dive?

 

[Divin'Papaw]

I can figure this out by looking at the dive tables, but I'm thinking the Perdix 2 should display this info while in surface mode. I know it tracks surface interval but I don't see any mention of displaying minimum surface interval in the manual. Like if I dive to 60ft for 40 minutes, will the Perdix 2 tell me how long I need to be on the surface before another dive?

There is no such thing. It all depends upon your plans for dive #2 and your gas.

 

[Ross19966]

I believe it does. I wonder if it gives minimum interval when you do a dive plan in the computer. I haven't tried that yet, but haven't really made any real dives with it yet either.

 

[Divin'Papaw]

I believe it does. I wonder if is gives minimum interval when you do a dive plan in the computer. I haven't tried that yet, but haven't really made any real dives with it yet either.

It allows you to tell it your SI (now, +15, +30, etc) & it tells you what your NDL is for each 10’ of depth. It can’t tell you min SI because again, that’s not a thing. You need to determine that based upon your dive plan.

 

[Ross19966]

Kind of what I figured but I was hoping. Thanks for confirming. Now to figure out what I did with my RDP card.

 

[Divin'Papaw]

Kind of what I figured but I was hoping. Thanks for confirming. Now to figure out what I did with my RDP card.

You can easily answer the question using the planner on the Shearwater. But you need to know your dive plan or goal … depth, time & gas. But the computer doesn’t know your plan so it can’t answer that question for you. BUT it can give you the data to answer the question yourself.

 

[tursiops]

Like if I dive to 60ft for 40 minutes, will the Perdix 2 tell me how long I need to be on the surface before another dive?

1 minute, unless you've changed the computer's settings. If you dive before the one minute is up, it thinks it is the same dive as the one you just "finished." After 1 minute, it is a new dive. That "end dive" setting can be changed from 20 s to 10 mins. Once it thinks it is a new dive, then you use the NDL Planner function to work out dive times allowable for selected depths. If you actually know what the next dive demands, such as 50 mins at 60 ft, then you can go backwards from that and determine your necessary surface interval to have had enough off-gassing. You do that in the NDL planner by adjusting your surface interval and seeing what is allowable.this is the equivalent to what you do with the RDP.

 

[Ross19966]

You can easily answer the question using the planner on the Shearwater. But you need to know your dive plan or goal … depth, time & gas. But the computer doesn’t know your plan so it can’t answer that question for you. BUT it can give you the data to answer the question yourself.

I see that now in the dive planner. When you input a surface interval I'm assuming it takes previous dives into account when listing the NDL at each depth.

 

[Divin'Papaw]

I see that now in the dive planner. When you input a surface interval I'm assuming it takes previous dives into account when listing the NDL at each depth.

Yes, of course.