Redundant buoyancy in warm weather

[down4fun]

Interesting thread. I'm nowhere near this level but I do like the idea of redundancy. What 40# smbs are you looking at? Are there one's made specifically for this emergency situation that are maybe a little stronger sewn together etc to reduce the risk of failure while you are "riding" it up? Is it preferred to have a smb or lift bag? It seems the lift bag might deflate when you get to the surface.

These closed smb's provide 40# of lift. So something like this
Halcyon Big Diver's Alert Marker, 4.5' long, closed circuit,

 

[Dr. Lecter]

These closed smb's provide 40# of lift. So something like this
Halcyon Big Diver's Alert Marker, 4.5' long, closed circuit,

Mine are these. One fits in the long pocket on my dive trunks or in my drysuit pocket, the backup fits in the storage pak pouch on my BP. Fully inflated, they'll float me, my double 130s full, and a couple of full stages. The 6' monster H makes seems like overkill to me, but is something I'd look at as redundancy for colder water dives with more stages and/or a scooter.

 

[geoff w]

I've been diving twice when my wing wouldn't hold air, once last year in the Bahamas with a 3mm wetsuit when the pull dump on the inflator hose came apart and an O-ring disappeared on my wife's wing (didn't realize it until we were diving, unscrewed the day before when washing gear, so I screwed it back together minus O-ring) and I swapped wings with her after her first dive, taking the wing that wouldn't hold air, and a few weeks ago for local shore diving with a 7mm wetsuit (accidentally punctured my wing the day before while rushing to wash everything before company arrived). The first time I knew in advance about the problem (my wife had a miserable dive), the second time I didn't. Both dives were hour long dives. If you're properly weighted, you can control your buoyancy pretty well with your breathing and minimal kicking. Before there were BCs, that's what divers did. Most divers are told they shouldn't have any air in their BC/wing during the dive, but few follow that advice. If you're close to neutrally buoyant during the dive without any air in your BC, maintaining flotation at the surface isn't even that hard, because your wetsuit is not compressed. Once you get used to diving with minimal (or no) lead, your trim will improve markedly and it will be very difficult to dive overweighted again

Of course, if you're in the tropics with a steel backplate and steel doubles, your 3mm wetsuit probably won't float you on its own, so you might want to plan gear configuration accordingly. Unless you have a catastrophic wing failure and it blows apart, there is usually some orientation that will hold a minimal amount of air (and in a pinch you can always get some air into your wetsuit to help with buoyancy)

If you're doing technical dives in warm, tropical waters, presumably longer dives with deco obligations, you're going to lose a fair amount of body heat during extended dive times, so why wouldn't you wear a dry suit? Several tech diver friends always keep telling me being warmer in the water reduces DCS risk, which I supose is another reason for wearing a dry suit when technical diving, even in the warmer, tropical waters

 

[RJP]

As tajkd mentions above, a tropical drysuit is a viable option. Below is my DUI 30/30 in South Florida. It has been to Hawaii, Bonaire, Curacao, Cayman Islands, Red Sea, Truk Lagoon, Turks & Caicos, Puerto Rico, Galapagos... and is going to the Bahamas next week.

Because it is wind-breaker thin, has no attached feet, and I wear thin poly undergarments I am far, far more comfortable at the surface - even in 100F temps - than I've ever been while wearing even the thinnest wetsuit. Here I am (photo courtesy of tajkd, as luck would have it) napping during a surface interval at noon in Bonaire on a 85F day...

My suit seems to fit me a fair bit better than tajkd's suit fits him (he's athletically built with broad shoulders/chest but like a 10" waist and spindly little legs ) so he's got a fair bit of extra material on his suit. The DUI 30/30 is more fitted in general than the Whites (and I'm less fitted in general than tajkd) so it fits me sort of cave-cut style.

I'm sure there's more drag than a wetsuit... but I've worn it in ripping current places (like Galapagos, for instance) and have never had anything approaching "a problem" due to it.

 

[The Chairman]

I dive aluminum when I am in the ocean. Problem solved.

 

[Nirvana]

I dive aluminum when I am in the ocean. Problem solved.

I am sorry, but I am not sure I understand what you are saying. As I tried to explain to Bob before, I am talking about a dive with doubles and deco tanks. Are you talking about using an aluminum backplate and aluminum cylinders, back gas and deco gas? I've dived like that (except steel backplate) and I was quite negative at the beginning of the dive, wearing a 3mm wetsuit.

 

[down4fun]

If you're doing technical dives in warm, tropical waters, presumably longer dives with deco obligations, you're going to lose a fair amount of body heat during extended dive times, so why wouldn't you wear a dry suit? Several tech diver friends always keep telling me being warmer in the water reduces DCS risk, which I supose is another reason for wearing a dry suit when technical diving, even in the warmer, tropical waters

Here in florida is it not unusual for the water temps to be 80-85F on deco. For an average 200ft dive with 30 minutes of bottom time and 60 minutes of deco that's 90 minutes in 80-85F water….you don't get cold. In fact you may even see us flushing our wet suits while hanging on deco because it's too warm.

It may be cooler at the bottom but this is to your advantage when it comes to decompression. Cold at the bottom and warm on deco is the best temperature combination you can have.

I have done as much as 6 hours diving wet utilizing a wetsuit heater.

 

[The Chairman]

I am sorry, but I am not sure I understand what you are saying. As I tried to explain to Bob before, I am talking about a dive with doubles and deco tanks. Are you talking about using an aluminum backplate and aluminum cylinders, back gas and deco gas? I've dived like that (except steel backplate) and I was quite negative at the beginning of the dive, wearing a 3mm wetsuit.

I still have to add weight to get me neutral. I usually dive doubles in a sidemount configuration, so no backplate for me.

 

[Kevrumbo]

Why baste in your own juices wearing a drysuit in the tropics?

The luxury & attraction of diving wet in 28 to 32deg C seawater is the soothing saline immersion in the "bathwater" liquid temperature itself --not to further irritate your skin in your own gritty/stinky perspiration for the duration of the dive by wearing a drysuit. For the long deco profile runs, I now utilize a UTD belt cummerbund heater to ward-off hypothermia.

I've been tech wreck diving Indo-Pacific tropical regions with manadatory deco now for seven years, using only a 0.5mil full skinsuit with a 3mil hooded vest underneath (Aluminum BP/W with AL 80's twinset, AL80 deco cylinders of 50% & 100% O2 & an AL80 stage tank of bottom mix, and no added extra lead on a weightbelt needed at all). I carry a tightly folded Halcyon Life-Raft attached to the bottom of my BP, for use as redundant buoyancy and for auxiliary survival surface flotation.

 

[mruseless]

Peeing in your wetsuit is definitely "basting in your own juices"...