Quiz - Skills & Environment - Overweighted Diver

[Angelo Farina]

The rates won't be equal and won't offset.

You will still be exactly correctly weighted at only one moment, which is what this sidebar is about.

It is not a matter of rates (which makes the diving profile not linear) it is a matter of equilibrium between two forces. The tank, emptying, pushes you up. The suit, compressing, pushes you down according to depth. You can adapt depth, so you can keep the forces in almost perfect balance for at least great part of the dive, not just one moment...
This was standard in the seventies, before BCD were in use. Most dives I did at that time were on steep slopes or vertical walls, so the depth was a free variable, which could be adjust searching for neutral buoyancy. And if the amount of weight was "proper", it was quite easy to find that equilibrium point.
Of course, if one is over weighted, being already negative at surface, going down one becomes even more negative, and the whole dive was dangerous and very fatiguing.
If instead one was missing, say, 1 kg of weight, it was not a big deal: instead of starting neutral at 10m, you are neutral at 15m, and from there you continue going down while the tank becomes lighter, keeping the two forces in equilibrium. It was easier to do than to explain, particularly to people who never dived without a BCD, nor can do a proper "capovolta" for winning the initial buoyancy in the first 5 meters.
These are lost arts....

 

[Ripley]

Since divers already plan to to wear their masks for hour-long dives, it shouldn't be a hardship and it quickly becomes a good habit to keep them on their faces for those few extra minutes between the time they surface and the time they climb out of the water.

Actually, when I overthink this statement, I must say you are right.
8 dives out of 10 I do are shore dives. When I get out, I remove my regulator and hang my mask under my chin as soon as I'm at a point that the water doesn't come higher than my waist. But the entrance/exit point is covered with pieces of concrete beams, rocks, etc.
I realize myself now that, even at that point, one can easily trip and fall.
Not removing reg and mask for 2 minutes longer until I'm actually out of the water wouldn't be such a bad idea.

 

[TMHeimer]

Actually, when I overthink this statement, I must say you are right.
8 dives out of 10 I do are shore dives. When I get out, I remove my regulator and hang my mask under my chin as soon as I'm at a point that the water doesn't come higher than my waist. But the entrance/exit point is covered with pieces of concrete beams, rocks, etc.
I realize myself now that, even at that point, one can easily trip and fall.
Not removing reg and mask for 2 minutes longer until I'm actually out of the water wouldn't be such a bad idea.

Agree. I always keep the mask on until back on the boat, or if a shore dive goes directly into deep water. Different story for walking to & from the shore on nasty terrain. That's when I consider the forehead.

 

[Storker]

I wear 42 pounds with my 7 mil farmer john. I should maybe know this, but what amount of lead would that probably translate to if I wore a drysuit?

That's impossible to answer. In a drysuit, the amount of lead you have to wear depends totally on your undergarments.

I've got two undersuits. One for summer (>14-ish C water), one for the cold season (colder than 10C water). The amount of lead I have to carry differs by about 4kg. In my previous suit (compressed neoprene, almost no undergarments), I needed a completely different amount of lead.

 

[Storker]

Actually, when I overthink this statement, I must say you are right.
8 dives out of 10 I do are shore dives. When I get out, I remove my regulator and hang my mask under my chin as soon as I'm at a point that the water doesn't come higher than my waist. But the entrance/exit point is covered with pieces of concrete beams, rocks, etc.
I realize myself now that, even at that point, one can easily trip and fall.
Not removing reg and mask for 2 minutes longer until I'm actually out of the water wouldn't be such a bad idea.

Last winter, I could have screwed up royally if I didn't have the habit of wearing my mask and keeping my reg in my gob unless I had dry land (or deck) under my feet. Shore dive. Slipped on a rock in knee-deep water. A bit of surf, heavily weighted, wasn't able to get up by my own. Face under water all the time. My necklaced secondary freeflowed (it was cold that day). Without a mask on and a reg in my mouth, what was an embarrassing annoyance could easily have turned into a somewhat sticky situation.

 

[scubadada]

I do much of my diving as live boat drift diving in south Florida, often with bigger seas. I always leave my mask on and regulator in the mouth for pick up. I generally hand up my flag but leave my fins on my wrists. Several times, I have lost the ladder and was glad for my caution. Once, I was ejected into the air off the ladder and was particularly glad I was prepared.

Many divers take their reg out and/or their mask off on calm days, they'll learn.

 

[tursiops]

I take my mask off and my reg out of my mouth when I'm seated on the boat/standing on the dry land. Old habit, learned the hard way.

 

[Ripley]

I generally hand up my flag but leave my fins on my wrists. Several times, I have lost the ladder and was glad for my caution.

Boat dives I remove one fin in the water, toss it on board, remove the second, toss and only then I step on the ladder.
I know myself: I can be very clumsy and it wouldn't surprise me that I drop one fin while removing the second.
Plus I want my hands free to grab the ladder (the frequent attacks of clumsiness again...)

Another reason I came to think of for keeping reg in and mask on: it could save you precious time when a fellow diver gets in trouble and needs help...

 

[dmaziuk]

Fair point.

Not really: it doesn't follow that an overweighted diver won't do it easier just because a properly weighed diver can do it easy.

 

[TMHeimer]

Last winter, I could have screwed up royally if I didn't have the habit of wearing my mask and keeping my reg in my gob unless I had dry land (or deck) under my feet. Shore dive. Slipped on a rock in knee-deep water. A bit of surf, heavily weighted, wasn't able to get up by my own. Face under water all the time. My necklaced secondary freeflowed (it was cold that day). Without a mask on and a reg in my mouth, what was an embarrassing annoyance could easily have turned into a somewhat sticky situation.

Yes, I admit that I have fallen maybe a couple of times in a foot or so of water and did already have my mask either on the forehead or in my hand. Think my reg was still in the mouth, not sure. Wasn't anything to worry about. Guess I got greedy and took it off a bit too soon so see where I was putting my feet on the slippery rocks. Either way, better to slip in a foot or two of water and go down than on slippery land. Well, unless for some reason you can get up in the water and your face is uw.