Surface Air Supply (Hookah) Systems

[alanfw]

I've been looking at options to allow me to go below the boat for cleaning and maintenance.
The cheapest I've come across is this:
https://www.ebay.com.au/itm/15475752...wAAOSw2XZhv9aK
It appears to just use a simple high flow rate aquarium air pump, so low pressure (negligible depth). I worry the pump isn't up to the task. It also seems expensive given the pump used.

Another option is this:
https://www.ebay.com.au/itm/37382899...0AAOSweaFhsfOr
Three times the price but looks safer and more flexible.

The final option is using a 12v compressor like this one and buying hose and stage 2 regulator from eBay, and probably a filter too.
https://bossairsuspension.com.au/sho...flation-combo/
(I did see another compressor tank combo that looked better but now I can't find it).

I'd like to hear opinions from people with more experience than me - that is, any experience at all!

PS: I already have a 54AH lithium battery I use to power my electric outboard, so that means the electricity supply is already sorted.

[tkeithlu]

I am (was, actually, the Admiral banned me from any more diving) an advanced open water type. I used to know a fellow deputy sheriff whose family got supplemental income from diving for freshwater clams using an oil bath shop compressor. Scared the daylights out of me. Nothing like petroleum products lining your lungs. Personally, I'd avoid hoked together rigs and buy a professional hookah system marketed by a dive company. Even when you are only eight feet below water, that thing in your mouth is a life support system.

[MikeHoncho]

I use a oil-less California Compressor 120volt compressor that supplies about 7.5 CFM that has a airfilter (looks like a toiletpaper roll and a 60 ft breathing air rated hose with a regulator. The whole set up cost about $800 and can supply two people if desired. I use a converted BA for buoyancy and about 30 lbs of lead with my drysuit. You can buy cheaper compressors but I wanted something with a small tank (aluminum) and something that had a low amp draw and was quiet. The compressor cost about $600.

[Pauls]

The California compressors are very good.

Tkelithu, long ago I ran a sea urchin diving boat. Urchin diving typically involved 6 hours plus bottom time a day, working hard and breathing like a lot of air. At the time there were about 30 urchin diving boats running out of Santa Barbara harbor. All of them, to the best of my knowledge, used oil lubricated compressors. There are two things done to make this safe. Firstly, the lube oil is drained and replaced with peanut oil. Non toxic and an effective oil for air compressors. Secondly, we all used a large filter on the output line, typically about 18" long, made from about 2 1/2" pipe. Two filtering media were used. A womens stocking was stuffed with long fiber surgical cotton and crammed into the first half of the pipe. Another stocking was filled with activated charcoal and this occupied the last half of the filter.

This set up worked very well. I suppose that there were 50 divers using it on a commercial level. The air output is sweet and clean. I've dove with this for hundreds of hours. An advantage of the oil lubed pumps is that they have a much longer life. Most dry pumps life is rather limited. If the guy you know used a set up like this he should be fine. Petroleum lube oil, on the other hand, is a really bad idea.

[Frankly]

If you happen to have an onboard diving tank (good for a lot of reasons) then you can buy a long hose to go between the first and second stages of your breathing regulator. Brownie makes a slick setup with some quick disconnect connectors. I have been using one to change props/ clean boat bottom for 25 years.


Frankly

[alanfw]

Originally Posted by tkeithlu

I am (was, actually, the Admiral banned me from any more diving) an advanced open water type. I used to know a fellow deputy sheriff whose family got supplemental income from diving for freshwater clams using an oil bath shop compressor. Scared the daylights out of me. Nothing like petroleum products lining your lungs. Personally, I'd avoid hoked together rigs and buy a professional hookah system marketed by a dive company. Even when you are only eight feet below water, that thing in your mouth is a life support system.

My research has enlightened me re the need for oil-free compressors. Everything I've considered so far is oil-free.
I'm astounded at the mark-up that is generated by connecting a few parts: it seems that $400 worth of equipment is cobbled together and sold for at least $1000!

[Spindrift NH]

I purchased a 12 vdc hooka from airline about 4 years ago. It was about $1,600 with the mounting plate. I like that it’s professionally made, tankless, and is powered by my house bank. It paid for itself within the first year.
I will say, keeping the bottom clean is a lot of work, especially if you have to deal with currents. I have great respect for the divers that do multiple boats each day.

[MikeHoncho]

Originally Posted by Spindrift NH

I purchased a 12 vdc hooka from airline about 4 years ago. It was about $1,600 with the mounting plate. I like that it’s professionally made, tankless, and is powered by my house bank. It paid for itself within the first year.
I will say, keeping the bottom clean is a lot of work, especially if you have to deal with currents. I have great respect for the divers that do multiple boats each day.

I agree. Mine has paid for itself in its first year with me having to switch out my prop 3 times and the bottom cleaning. I'll be a couple more years before I pay off the dry suit. That is what makes this project pricey.

[Simi 60]

Plenty of previous posts on here covering this

We use a 240v oil free compressor with 24 litre tank from the big hardware store

A water trap, 50m of proper breathing hose and a reg bought on ebay

Total cost of this setup was under $250

Done near 70 hours on it so far, all good

[fstbttms]

Originally Posted by Pauls

The California compressors are very good.

Maybe, but I like my compressors to be made in this country.

Originally Posted by Pauls

An advantage of the oil lubed pumps is that they have a much longer life. Most dry pumps life is rather limited.

In the hull cleaning industry, American-made Thomas and Gast oilless compressors are at the heart of the best commercially available and DIY hookahs. Yes, they cost more than the Chinese junk but they are rock-solid reliable and safe to use. They last for years. Nobody doing in-water hull cleaning is using an oil-lubricated compressor. There is no need for them.

[sailingabe41ds]

How dumb can I be...I thought California compressors were really made in California USA.
abe

[denverd0n]

I will just put in the obligatory reminder to get dive training before using compressed air underwater. Yes, for bottom cleaning you are not going very deep. But you don't have to be very deep (4' deep is plenty) to kill yourself if you don't know what you are doing.

[alanfw]

Originally Posted by denverd0n

I will just put in the obligatory reminder to get dive training before using compressed air underwater. Yes, for bottom cleaning you are not going very deep. But you don't have to be very deep (4' deep is plenty) to kill yourself if you don't know what you are doing.

That's worthwhile advice. I've done plenty of free diving but only one "resort dive" with scuba gear. Often thought of doing a proper course, but until now never had a good reason. I've got a background in science (physics, chemistry, electronics) so have a pretty good understanding of the theory.

[michaeld]

I used to dive four to six tanks each weekend chasing spiny lobsters or exploring wrecks breathing partial pressure Nitrox mixes: normally 40% O2. I haven't done much "diving" for fifteen years or so, but I have done most all of the bottom cleaning and changing zincs.

I prefer my 80 lb tank, air filled, with a Brownie's Hookah configuration. A decent scraper and a BBQ scrub pad is used to clean the bottom... Trinidad Pro. I can normally get to cleanings from one tank fill on a three week rotation.

[Jammer]

I scuba dive a fair amount.


I am skeptical of the inexpensive hookah systems. There are many people who use them without incident, but I question the quality of the air they deliver. Responsible shops that fill scuba cylinders send air samples to the lab periodically to confirm an absence of contaminants. As a result the compressor/filtration design and maintenance practices have been refined over the years as causes of contamination are identified. Some divers test every cylinder for CO.


Risks are lower with low pressure hookah systems (most operate at around 90 PSI rather than the 3000 PSI common in cylinder fills), mainly because they run cooler, but they still exist.


There is, as far as I know, no centralized collection of accident or safety data regarding hookah diving, from which to determine the safety of the activity or best practices.