Surface interval

[PADI Knight]

Planning some dives for next week and trying to get in as many as I can in running the RDP I got thinking (I know stop that you'll get hurt). Just truly is a surface interval. In OW class mainly we floated on the surface for the time we needed. While the manual mentions as the time between dives. Since my instuctor has moved to the Virgin Islands I thought I'd ask some of you more experienced divers what's the general idea on what's counted as a surface interval?

 

[bclancey]

I count it as the time I exited the water till the time I return. This gives me certainty about the interval. Since bottom time is calculated until you start your final ascent, some people might count surface interval starting at that time. But, I wouldn't.

 

[Damselfish]

The surface interval is simply the time on the surface between dives. Most dive computers will have some period of time (a few minutes) during which if you go back down it considers it the same dive, therefore it's not a surface interval. The PADI table shows intervals starting at 0 minutes so according to that I suppose a surface interval could be a nanosecond long. But since it takes at least a few minutes to go down 1 pressure group maybe you could say that's what it takes to call them separate dives.

Not sure why it matters though, practically speaking. Are you trying to see how many dives you can do just as table practice, or planning on diving that way? Which would not really be such a hot idea and kind of pointless. Classes sometimes aren't conducted like real dives. You probably didn't spend enough time or go very deep to need much time up if any, it almost sounds like you were doing a surface interval for practice, or just so it could be called 2 dives. In real life you would get out of the water, change tanks, do whatever, and typically spend at least 40-60 minutes out to reduce nitrogen enough so your next dive isn't cut short.

 

[TSandM]

Surface interval is time on the surface. Time spent floating or swimming in could theoretically be counted.

Surface intervals can be as short or long as you make them. You should remember from doing the tables in OW that, if your SI is short, you will pay a higher price in shortened bottom time on subsequent dives. In addition, some tables require a certain minimum surface interval (NAUI nitrox tables, for example.)

 

[Scuba_Steve]

SI is not started from the time you start your ascent, it starts from the time your head breaks the surface at the end of the dive.

Good thing you guys were taught so well. That's not a slam on you two, but more so what you've either forgotten due to fast-paced training or weren't taught at all.

BTW: For the record PK, you're dives during your course must including exiting the water, de-kitting etc, and then re-entering the water after again gearing up, to count as separate dives. The point here is because they were training dives, evidently conducted through Padi.

Check number two for the training, but don't sweat it as I see knuckle head Instructors do this one all the time.

 

[Fish_Whisperer]

I was taught that if you surface for five minutes or less and then head back down, it's all counted as the same dive. If you are on the surface for longer than five minutes, than you have begun your surface interval, and after that five minutes, if you descend again, you have just begun a second dive.

 

[H2Andy]

SI is not started from the time you start your ascent, it starts from the time your head breaks the surface at the end of the dive.

Good thing you guys were taught so well. That's not a slam on you two, but more so what you've either forgotten due to fast-paced training or weren't taught at all.

well, dude, read the posts. nobody said that.... bclancey said some people
might, but he wouldn't. anyway...

your surface interval starts the moment you stop breathing gas under pressure
(breathing gas at the surface counts as surface interval; breathing gas
one foot under doesn't).

 

[Al Mialkovsky]

Surface Interval is time on the surface, between dives. If it's less than 10 minutes you factor it as one continuous dive. If it's over 12 hours, it's a new diving day.

 

[Walter]

Al hit it perfectly. If you floated on the surface between your dives, your instructor did you a disservice.

 

[PADI Knight]

Nope we got out twice and doffed and doned ate lunch during one break the other dives we just floated and doffed and doned gear on the surface. Except for the navigation we had to snorkle a corse on top head down and then run the same one at 15 ft. I was off by only a few degrees underwater.