Basic dive equipment for occasional use on boat

[Mervyn Charles]

Hi
Many years ago I did BSAC 3rd class and most of 2nd class diver training. But things have change from the days of ABLJs
Can someone recommend what I need for a very basic kit to be used occasionally for rescuing anchors etc. Checking hull of boat. max depth 10m.
Thinking a small 3L pony tank. How long would that last at 5m. Can it be attached to any simple stabjacket.
Will not be using wetsuit. Will I need any weights?
Many thanks for your help.

 

[HantsDiver]

How long the gas would last depends on you and how you are affected by things.
Same goes for weighting.

I'd be looking for a 7l as a minimum though.

 

[Centrals]

3L at 200 bar will give you 600 FREE Litre of gas. How long would it last is totally depend on your consumption. And your gas consumption is depend on eg. work load. Please also remember your gas consumption at 10m is twice as much as on the surface.
Do you need any weight? You have to find it out yourself preferably with an near empty tank.

 

[Diving Dubai]

Hi

As you info states from London I've done this in metric

A 3L cylinder filled to 200bar (assuming it's aluminum not steel) will hold 600L gas (volume X pressure)

Assuming a Surface Air consumption of 20L a minute which will be 40L/min at 10 metres (2ATA) Would give you about 12 minutes assuming you leave yourself 50 bar as a reserve Obviously if your air consumption is better or worse then the time will chage accordingly

200bar - 50Bar reserve = 150. Multiply by cylinder size 3L = 450 litres. Divided by SAC X ATA (40) = 11.25 minutes

If you only went to 5m this would extend to 15 minutes

I wouldn't recommend this for rescuing an anchor I'd go for a full size 11L (or whatever larger cylinder is available locally) because you'll have a greater consumption faffing with an anchor and will also want to use a lift bag to raise it - all which uses more gas You'll often see Steel 12l tanks on UK Ebay for less than 100 pounds. Alternatively a Steel 7 litre new is 160. (Steels are rated at 230 bar so for a 7 litre you'd get around 30mins - a 12l cylinder nearly an hour - depending on air consumption) New Scuba cylinders normally qualify for free delivery

As for weights, yes probably. All depends on you build, and weight of equipment. For me it would only be a couple of kgs, but we're all different. You'll need to carry out a proper weight check to confirm.

A 7l or greater you could fit to a Stab jacket, a 3l would need some faffing about

 

[Mervyn Charles]

Many thanks for all the replies. Very useful. Sound like 7L is the best option

 

[Mustard Dave]

Without wishing to be discourteous, your post suggests you are well out of practice. Working out air consumption is basic stuff; a competent diver should not have to ask on the internet. Even though you are only talking about brief and shallow dives, you still need to be competent before jumping in the water in scuba gear.