Using Shearwater Computer for Recreational Dives

[UncleJaybles]

So, I'm relatively new to the tech diving community. Still, many of my dives are purely recreational as I still have a lot of photography friends who aren't tech trained and/or some of the dives I like to do just aren't tech dives.

However, I have to say that I have fallen in love with using my technical computer (Shearwater Petrel) over any of my recreational computers. This is mainly because I find it so much easier to read and it is much easier to navigate through the menus. However, when I am diving with a recreational crowd, I notice that the usual gradient factors and/or conservation factors don't get me the same no-stop time as people diving with recreational computers.

I'd like to switch over entirely to using my Shearwater. Has anyone out there found settings for the Buhlmann/VPM/VPM+GF algorithms on the Shearwater that more closely approximate the DSAT/RGBM algorithms that are more commonly found on recreational dive computers?

 

[ElGaucho]

Whenever I use my Predator for rec dives I find I end up hitting deco way too soon with my usual settings for tec diving (VPM +3 or 10/80 GF). The thing is finding a good balance, I believe I would use VPM+1 or even straight for rec dives. Also, it will not do a safety stop countdown or anything like that, but Im sure you can do your own safety stop. I usually do 3 mins at 20-15ft, and then ascend for 3 minutes to the surface, since that´s what I usually do on my tec dives (very slow final ascent to the surface). Again, I usually dive with a "sort of" GUE mindeco profile anyhow (10ft per minute for the upper half of the ascent), so by the time Im at 20 ft, Im pretty much clear of any further suggested obligations. Again, I enjoy spending time at shallow depths, so I take my time.

Quite honestly, if you take your time to understand a bit about deco, and you take every dive as a deco dive, and understand stops are a matter of actually making very slow ascents, you can dive any computer and do sort of a balancing act as you go, at least I do when I dive my Shearwater on a rec dive. I will happily rack up some minor time at 20, since I understand what´s going on and what that entails from experience. My only recommendation might be to take a "regular" dive computer for the first dozen dives alongside to be able to compare the conservatism ratings in your usual rec dive against the Shearwater.

Like anything relating to deco, it´s about what you are comfortable with.

 

[HIGHwing]

Yes. Try 30/85, it's close enough to be compatible with most recreational dive computers.

 

[Dr. Lecter]

VPM 0 is what I use for normal rec dives, VPM +1 for things in the 100-130' range where I plan to rack up 20 or fewer minutes of ascent time if I go into deco at all. The Petrel is ridiculously conservative on the NDLs compared to the Cobalt I used to use, I think the comparison I did when I got the Petrel was that VPM 0 provided the same NDL for a given exposure that the Cobalt on its most conservative settings gave.

Though it really is whatever works for you: at the other end of the spectrum, I've gone so far as to set it for VPM +3/75 for long, deep air exposures because I find just +3 provides insufficient deco when combined with the need to muscle a mess of doubles and stages back aboard a tiny boat right after surfacing.

 

[ajduplessis]

30/85GF and VPM +2 should do the trick.

 

[UncleJaybles]

Thanks everyone for the responses. It seems like the VPM +0 suggestions runs pretty close to my current rec dive computer for dives in the 50-80 foot range (though I'm just looking at the planning modes right now and haven't actually compared them in the water). Beyond that, the VPM +0 actually feels like it might be getting a bit too liberal for my tastes. I might reel it back to VPM +1/2 for those deeper dives, especially because I'm still likely to wear doubles on the deeper dives, which is a lot of weight to get up on the boat.

I'll definitely be keeping my recreational computer with me just to compare how it functions on multi-level real life scenarios... at least for the first couple dives. Thanks again for the suggestions. All very helpful.