Challenge: The Wife Wants . . . SCUBA

[bodhi02]

Originally Posted by roverhi

Once we got in shape, free diving would get us down as deep as 60' without much of a problem and provided us with much of our protein from spear fishing. The secret to free diving is weighting yourself to just slightly negative buoyancy. Without weights, you waste most of your energy and air getting down to about 15' where the pressures compress your body enough so it loses buoyancy. With the weights, you just get yourself pointed down and give a couple of kicks to send you deep with almost no energy required. After a but of time free diving everyday, was able to get to some pretty extreme depths and/or have plenty of bottom for exploring or hunting.

No! Absolutely not! Being negative at the surface is asking for trouble. Yes, it makes it easier to get started down, but it also means that it is harder to get up, which is when you need to be working the least. Good tuck technique gets you down through the first few feet no problem, and then when you are on your way up, especially the last 20-30 feet when you have the greatest expansion of air volume in your lungs, and thus the greatest potential for shallow-water blackout, you can simply drift up to the surface without expending any energy. If you did stay down too long, and start to black out, you will still hit the surface as opposed to sinking into Davy Jones' Locker
Additionally, being negative at the surface means you have to work just to stay afloat, when you should be relaxing and recovering between dives. I often spend 3-4 hours in the water, free-diving on a constant cycle of about 2-3 minutes on the surface followed by 2 minute dives to depths of 60-100 feet. If I had to burn energy just to stay afloat, I would not last nearly that long.
There is a huge difference between actively free-diving and merely snorkeling around. It is also much more dependent on being comfortable in the water and having solid technique than SCUBA diving, which is basically like going to the aquarium and staring through the glass.
If you start free-diving regularly, you will never go back to SCUBA, but please be safe.

[roverhi]

Yes, absolutely yes. Notice I said just slightly negative. The way a lot of people are naturally. Takes very little effort to stay on the surface as I am not advocating going way negative via the weights. Would spend hours in the water this way spear fishing or just exploring. It was way less tiring than trying to free dive without the weights.

Just got back from Fiji and didn't take my weight belt. A total pain to get that first 15' of depth and little endurance because of all the work to get down that little distance. It was really a problem trying to take pictures as I'd float away from anything I wanted to shoot without kicking like hell to stay down.

[downunder]

Originally Posted by bodhi02

No! Absolutely not! Being negative at the surface is asking for trouble. Yes, it makes it easier to get started down, but it also means that it is harder to get up, which is when you need to be working the least. Good tuck technique gets you down through the first few feet no problem, and then when you are on your way up, especially the last 20-30 feet when you have the greatest expansion of air volume in your lungs, and thus the greatest potential for shallow-water blackout, you can simply drift up to the surface without expending any energy. If you did stay down too long, and start to black out, you will still hit the surface as opposed to sinking into Davy Jones' Locker
Additionally, being negative at the surface means you have to work just to stay afloat, when you should be relaxing and recovering between dives. I often spend 3-4 hours in the water, free-diving on a constant cycle of about 2-3 minutes on the surface followed by 2 minute dives to depths of 60-100 feet. If I had to burn energy just to stay afloat, I would not last nearly that long.
There is a huge difference between actively free-diving and merely snorkeling around. It is also much more dependent on being comfortable in the water and having solid technique than SCUBA diving, which is basically like going to the aquarium and staring through the glass.
If you start free-diving regularly, you will never go back to SCUBA, but please be safe.

Working in metric 1kg = 2.2lbs
Rough maths.
Just say you need 5kg lead to counteract the buoyancy of your wetsuit at surface.
Wetsuit buoyancy is 5kg and your lung volume 6 litres
Wetsuit at 10m (33ft) has positive buoyancy (rough) of 2.5kg and at 20m (66FT) of 1.7kg or negativly bouyancy of 2.5 and 3.7kg respectively.
Lung air at 6 litres = 6kg positive at surface, and a loss of 3kg positive at 10meters depth and 4kg at 60ft depth.
i.e. free diver will lose positive bouyancy of 2.5 plus 3kg = negative of 5.5kg at 10m and 3.7 plus 4kg = negative 7.7 kg at 20 meters depth.
FREE DIVING weighted such to a depth of 60ft trying to swim off the bottom at over 5kg negative buoyancy is just dangerous and many have drowned not understanding the basic physics. An experienced freediver could safely consider diving shallow water 10-15ft being slightly negative but never deep water.
REMEMBER being negative means you sink if you stop swimming. Experienced freedivers working 60ft would likely weight themselves to be neutrally buoyant at 26-30ft. Sure you need a good technique but necessary for safety. If you black out you end up on the bottom where many have.

[downunder]

Originally Posted by roverhi

Yes, absolutely yes. Notice I said just slightly negative. The way a lot of people are naturally. Takes very little effort to stay on the surface as I am not advocating going way negative via the weights. Would spend hours in the water this way spear fishing or just exploring. It was way less tiring than trying to free dive without the weights.

Just got back from Fiji and didn't take my weight belt. A total pain to get that first 15' of depth and little endurance because of all the work to get down that little distance. It was really a problem trying to take pictures as I'd float away from anything I wanted to shoot without kicking like hell to stay down.

You need that neutral boyancy to successfully get those shots. Agreed.
I am deep reading reading your words.

[TeddyDiver]

Originally Posted by callmecrazy

If the weight and space is the biggest concern, consider scaling down the gear and practice the 'tropical minimalist' way. Which is basically skipping the BCD and weight belt in favor of a backplate with no wetsuit. All you really have to make space for is the tank.

Concur.. maybe space for two tanks thou

[category4jay]

I found this thread very interesting but not really because of the OP's question. By all means take the SCUBA gear if you have the space. Hell why not? But what I found interesting here is that it seems by the replies of people that there is a lot of solo SCUBA diving taking place by cruisers. Being an Advanced Open Water trained diver myself I have always been trained to NEVER dive without a dive buddy. OK so I get the occassional solo hull check, freeing up of the anchor, lost gear search, or just a quick dinner grab scenarios but how many people really dive solo to depth (basicall deeper than 33ft)?

[offline]

I feel pretty well qualified to answer this.. I am a long time diver and hold instructor-trainer certifications from all three major organizations in both recreational and technical skills through rebreather.

I will solo dive to depths greater than 33'... but that ONLY happens when I am on a dive boat with a professional captain that knows my skill levels and is comfortable with this... never ever will I solo to depth off my own boat without someone who I implicitly trust on the surface.

If you are an experienced diver (hundreds of dives, not dozens), with good local knowledge, in the proper conditions (calm, no current), with the proper gear (larger pony bottle on a spare regulator) and with a simple dive plan there is no reason why some simple dives can't be done solo.

However the recreational agencies mandate buddy diving because most divers only get wet occasionally and although certified may lack the knowledge and skills to properly self rescue or keep themselves out of trouble. And anything that has ANY sort of overhead environment, involves any potential risk of developing any sort of decompression obligation or has any task loading potential not a candidate for a solo.

[daddle]

On a 30' cat. No, I'd rent. Too heavy. And the next thing she'll want is a compressor for refills. Then you'll be buying a larger boat...then more tanks...you see where this is going.

[lorenzo b]

The diving and reefs off Florida are a bad joke when compared to the Mesoamerican Reef off Belize and Honduras. The fish are more plentiful but the coral is dead. You do see some companies still taking people diving in Key West, but most snorkel.
In Utila, Honduras you can dive for $30 / dive with guides and support.

[category4jay]

Great answer Offline! Thanks. Individuals with your background, experience and training should certainly be able to dive solo given the right combination of circumstances and variables which you outlined above. I just wonder how many cruisers out there who are NOT nearly as experienced choose to dive solo anyway. Have you heard of any horror stories in Florida related to this?

[MarkJ]

Take the SCUBA kit.
It is useful.
Often when near good dive spots you will find a dive boat and often they will have a compressor on board.
Always keep your tank full so you can do anchor recoveries, and for cleaning the keel.

Be regimented with the cleaning of kit.

[Knowazark]

From my experience, I'd say that most dives are solo anyway .... even when you have a buddy.

Unless your buddy is RIGHT THERE, in your face or glued to your side you're pretty much on your own. I've dived in visibility conditions where my buddy was only 10-15' away and almost completely out of visual contact .... certainly wouldn't have been able to see or interpret any visual signals. So, either you have someone constantly bumping into you or getting in your way or kicking you in the face, scaring away the fish just as you're about to take the photo, etc .... or you get some separation but you're pretty much on your own if anything goes wrong.

I'm planning on carrying SCUBA gear but being the only diver on the boat. I anticipate doing short solo dives to clean the hull, clear a fouled prop, retrieve a stuck anchor, etc .... maybe a quick food gathering dive (maybe!) but if I want to do a scenic dive I'll get myself onto an organised dive trip. The dive trips will all know about interesting places to dive, the local hazards, will have air fills and tanks, can organise a buddy, etc, etc.

[osirissail]

Originally Posted by callmecrazy

If the weight and space is the biggest concern, consider scaling down the gear and practice the 'tropical minimalist' way. Which is basically skipping the BCD and weight belt in favor of a backplate with no wetsuit. All you really have to make space for is the tank.

If she is worried about not having a "buddy" while she dives go one step further in the above advice and have her skip the wetsuit and bathing suit.

[capn_billl]

I agree the the reply on negative bouyancy, TOO Dangerous. If you really need the boost to go down the first 15 ft carry a weight tied to a bouy with a 15-20' line. That way you can ditch it when you don't need it, or when you need to surface. The old pearl divers would hand carry a large rock.

I found plenty of things to see in Dry Tortugas by snorkal. If you have the gear though, there are always things to see and places to go that are deeper.