Sherwood Wisdom 1 computer question

My bf and I have the Wisdom 1 computer and can't figure out how the "Safe Time" is calculated. It seems to factor in your remaining air with the depth, which can give one of us (whoever happens to be the air hog on any given dive) a much shorter dive time than the other. If this is how the "Safe Time" is figured, is there some way to just show NDT when at a given depth?

Thanks!

kpetro:

My bf and I have the Wisdom 1 computer and can't figure out how the "Safe Time" is calculated. It seems to factor in your remaining air with the depth, which can give one of us (whoever happens to be the air hog on any given dive) a much shorter dive time than the other. If this is how the "Safe Time" is figured, is there some way to just show NDT when at a given depth?

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I'm not in any way affiliated with Sherwood Scuba. Perhaps I might be able to help, though.

As you already know, the Dive Time Remaining area is where "Safe Time" is displayed. DTR shows the lowest number of the following the values: No Deco Time (at the current depth, how long you can stay without going into Deco), O2 time (at the current depth, how long you can stay without violating O2 exposure limits -- helpful if you're breathing nitrox), or Remaining Air Time (at your current breathing rate and depth, how long you can stay without running out of gas).

If you are breathing regular air, DTR/"Safe Time" will show the lesser of: No Deco Time or Remaining Air Time.

The situation you inquired about is one in which, during a dive, Remaining Air Time is the limiting factor. You asked if it would be possible to display the No Deco Time in this situation. I suppose you can try to hit the Select button (on the righthand side of the computer) to see if there's an alternate display mode that shows No Deco Time. However, I don't think there will be. If you want to get a handle on nitrogen loading at that point in time (when Remaining Air Time is displayed), I'd recommend looking at the Nitrogen Bar Graph on the lefthand side of the display. When the nitrogen bar graph hits the "red" area, essentially you have run out of No Deco Time (goes to zero). If you think about it, the Nitrogen Bar Graph is actually a graphical illustration of No Deco Time.

Hope this helps a little...at least until an official Sherwood Representative can compose an answer to your question.

I'd suggest get a non-air integrated computer and call it a day.

Until you get a definite answer, I would try to read through your entire manual if you have it.

Good question! I also wonder why my computer made me do a couple of 'deep stops' on our recent dives. The only difference between my dive and my dive buddy's (who has the identical computer Wisdom 2) was that I'm an air hog...lol. I always do what the computer says though...never piss off your computer.

Thanks everyone, that was what we were thinking too. We dive Nitrox, but it doesn't seem to matter when % we use. I have read the manual, but it's not real detailed. We always follow the computer, but we were curious about this aspect. Another thing it does is give a long bottom time when in plan mode, but as soon as we hit the water it drops significantly. Oh well, guess we need to work on air consumption.

kpetro:

Thanks everyone, that was what we were thinking too. We dive Nitrox, but it doesn't seem to matter when % we use. I have read the manual, but it's not real detailed. We always follow the computer, but we were curious about this aspect. Another thing it does is give a long bottom time when in plan mode, but as soon as we hit the water it drops significantly. Oh well, guess we need to work on air consumption.

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It sounds like the Plan Mode assumes that the dive will be limited by No Deco Time.

Nitrox simply won't help extend bottom time on dives that are gas supply-limited.
You'll end up breathing the nitrox mix just as fast as regular air.

On the other hand, nitrox will help lengthen bottom times if the dive is limited by No Deco Time.