Determining surface interval between dives when at multiple depths during the dive?

[rick00001967]

some of the comments are interesting. i have personally never been advised to ever use standard dive tables to plan multilevel diving. as one mentioned above, "the wheel" was an advanced type manual device used to do this before computers came into the picture. but i don't know anyone who uses one nowadays.
most dive ops i have dived with simply plan a max depth for a max time (well within the ndl) and if it turns out to be a true multi level dive, and the max time is not exceeded, thats even better. but you would still use the max depth and time to calculate your si with the dive tables. this is why computers became so popular. they will give you a better calculation. but remember.....computers are only a hypothetical estimate of your bodies nitrogen levels. so you should never follow it as gospel. don't push its limits. leave some room for error. especially when doing multiple days of repetitive dives.

 

[redacted]

I use tables with 0 SI to get a ball park estimates of PG at the end of the dive and go from there. Some suggest adding a PG. Another correction you could consider is adding a couple minutes to BT to allow for the ascent you did not do. But the result is a ballpark figure that you would not want to use to push to the limits in an actual dive. Manage the actual dives series on your computer in the water.

BTW I do quite a few dives like you describe (often with shorter SIs) and also use an Oceanic Data Plus. In my log I add the TLBG results so I can use those logged dive sequences as another reference in planning future dives. My rule of thumb is to normally stay out of the caution zone (yellow). I doubt if the series you describe will go very far past the middle of the green - Maybe 8 or 9 of the available 12 green ticks on the TLBG. If you find you are getting more loading than that, you may want to switch to Nitrox.