SCUBA compressor solution?

I’m looking for a scuba air fill solution for cruising. It seems worth it having a SCUBA compressor on board (vs getting your tanks filled at a local shop). I’ve read lots of debates about gas vs electric compressors, the hassle of maintaining a compressor on board, the danger of having your own compressor, fumes, maintenance, etc. I’m looking for feedback on what folks have done that works. I have a 5kw diesel genset (marginal I’m told for a electric compressor) and run diesel on board so I’m not excited about running a gas compressor but my dinghy is gas so I always have some gasoline anyway. Anyone have the perfect solution?

That can be a long discussion. You should start with some calculation of what size compressor you need. Could you live with a 2-4 cf/min unit? Bauer various/utilus are serviceable units for something small. Then Rix 3a/6a, also serviceable. Keep in mind, dive compressors on a small boat are going to be relatively slow and fairly loud. If you are doing more than topping up, you won’t make friends. Personally, I’d go with a full station at home in a sound enclosure. It’s usually less hassle to just bring a couple extra tanks with you.

We fill in port now but it limits time at the dive site in remote areas (i.e. south Bahamas) esp if you want to hang out on the hook. Looking for feedback on what people are actually doing now.

Here is a good site for resource information. The Dive Mate portable can be fitted with gas or diesel motors also. Breathing Air Systems - Home.

I bought a gas one, MCH6 in a box. The cover is weatherproof, but removed when using it, so not sound proofed. I have it up on the boat deck.
https://www.nuvair.com/products/compressors/hp/mch6-weather-proof-dock-box.html

It has a Honda motor, and is quite a good unit, and not excessively noisy but in a tight/full anchorage you may well irritate some folks. Just use it at reasonable times of the day.

But it doesn't get a lot of use. I was planning an ocean crossing at the time and wanted to be able to clean nets/ropes off the props as and when required. I think I would go for electric in the laz or ER if doing it again, easy to rig an intake snorkel to get good air inlet.

Your 5kw genny should easily manage a single phase electric MCH6.

Keeping a bunch of tanks in test and full could be a better option, if you have a good storage space for them.

I've had, over the years, 3 portable compressors on small boats. We took a gas one with us to San Sal on a 27' boat. Before that, a small electric powered from the 42 trawler's 8kW genset. My last compressor was a 4 man carry gas unit, that we did continuous blending with. Using 250cf O2 bottles to get 33% nitrox in double tanks. We've recharged on top of the Bimini wall while tied to a bouy and had long fill hoses run to the dinghy.
Some other scenarios: We recharged on the beach with a portable. One time, we planted a compressor in the Bahamian woods for an entire week, under a picnic tent, keeping 4 doubles divers supplied with nitrox.

I guess what I'm saying is that many different modes are possible. Bring ear plugs.

While it's attractive to own your own compressor, from a cost perspective it's a looser. People visualize doing a lot of diving if they have their own compressor. Reality is they don't. People think after purchasing the compressor, the fills are free. They're not. There is a significant cost to running and maintaining an air compressor. A far better investment is to invest in a dozen used tanks. A retested tank costs about $100. A dozen would cost you $1,200, weigh about 500 pounds, and take up a foot print of 23" x 30". While you will periodically need to find a place to fill them, the time factor is substantially less than the numerous hours to fill them yourself. The only justification for owning your own compressor is traveling in areas where you won't pass a dive operation for weeks or more.

Ted

San Sal has fabulous diving, but the local dive shops won't fill your tanks if you don't dive with them. Yes, if you hang around freeport, bimini, and nassau, you can get fills. But, then you are stuck in those places. The OP mentioned S. Bahamas. You will need a compressor. I'm not even sure if Cat Island even has a compressor.

My mid sized compressor weighed and about the size of 2 x 80's.

O C Diver has the best advice.

The best setup is a compressor off a diesel and a tank farm. The small gas motor driven compressors take a long time to fill a standard tank. You burn a lot of gasoline. With 4 people diving, it runs all day, if you have the spare tanks. Otherwise you take a 2 hour break waiting for the tanks.

The compressor intake needs to be where it can draw clean fresh air. An intake filter is a good idea.

Great feedback, thanks. My boat is a 32' Cat so there is not much room. The noise is something to think about, seems like most of the electric compressors are 220... have to see it that is possible with my 5kw northern lights - but the getset is fairly quiet and if I run a gas powered compressor I'll probably have to bring it up on the flying bridge and that will just broadcast more noise.

5kW NL gennie sold in the US market can be wired for 240v. Most are set up for 120v, but a simple change gets you 240.

My previous boat was a 38’ sport fish and I replaced the fighting chair with a 48” x 48” x 40” kill box that could carry 36 luxfer 80s plus suits and other assorted gear. We dove 30 30 trimix which we blended at home and put on the boat. There simply was not enough time or weather widows to be filling tanks offshore to even think about bringing a compressor. We figured If your gonna dive you should just do it right. I’ve had Bauer Jr’s on boats before. Not anymore, I think investing that money in a performance free diving class or two will give you a safer and better return especially for the Bahamas.

A typical air compressor from a box store can only handle 150 to 250 psi where as a scuba tank requires anywhere from 2700psi up to 3600 psi some tanks can handle more or check more options: air compressor for home garage . I'm sure so the they use at the dive shops are super heavy duty and have anywhere between two and 3 stages of compression before it pumps the air into the storage banks.

I realize this is an older post, but I thought I'd add to it anyway. I posted this reply on another thread. We just picked up a Colti MCH-6 used. Similar to the Bauer Junior, but not as pricey. Ours is 220v, but also available in 110v, and gasoline engine. The MCH-6 we bought will fill one 80 cu ft tank from empty (300 psi) to 3100 in about 22 minutes. Uses a 220v electric motor. Ours has the optional automatic condensate drain system ($440.00), and optional ($175.00) manual set shut off pressure valve, which would have brought the price new up to a little over $3,000.00. We found our at a pawn shop of all places. Probably used to fill up paint ball cylinders since the scuba yoke was missing. Like new condition, all parts available from www.nuvair.com, the US distributors. Their tech/parts people were absolutely FANTASTIC! Worked with me before the purchase on what to look for, what to avoid, recommended price to offer, etc. They were asking $2,000.00, I paid $950. Including 1 gallon of compressor oil, spare filters, new yoke, etc, I have about $1,100.00 into it!
Bottom line, for light duty maybe 3 or 4 fills a day, they're several good brands out there. Oil change every year or 50 hours of operation (that's about 136 tank fills) and periodic inlet and oil scavenge filter change, and you're all set! I DID add an hour meter to better keep track of usage for maintenance. . . .

If you look at the price of the compressor, periodic maintenance, etc, it may not be economical to buy a compressor, BUT we are looking for our next boat and planning on spending a LOT of time in Bahamas, Florida, Caribbean, etc, so it's more about convenience, than about cost. Plus it's not necessary to carry as many tanks, or deal with trying to find someplace to fill tanks while anchored near some of the outlying islands, or whatever, need to fill, fire up generator, or better yet, wait until you are running the generator for other things, water maker, etc, fire up the compressor, and fill tanks at the same time. Only draws 14 amps, and will fill to 4000 psi if needed.

Now just need to boat to go with it . . .

thanks for the update... we still haven't decided what to do... hopefully heading to Mona Isl where there are no air fills but with a group that has one. LOVE your pawnshop solution, we'd be all over that one...

A buddy of mine has his HP compressor running with a hydraulic motor which runs through a PTO from the main engine. Ores well for him although a bit of a chore to set up if I remember.