You know from your nitrox class that the US diving industry reached a consensus several years ago that most scuba equipment does not have to have special treatment as long as you are using enriched air with an oxygen concentration below 40%. (Check your owner’s manual to get the details for your particular gear.) This is not the case in Europe, and even in the US does not necessarily apply to your tank and valve.
In your class you learned about proper labeling of your tank, but you should also be aware that your tank and valve may require special cleaning in order to be properly prepared to be filled with enriched air. This is because one of the common methods of making enriched air is to introduce pure oxygen in to your tank, then topping it up with air to obtain the requested O2 percentage. Since the tank and valve are exposed to pure oxygen during the filling process, they can represent a hazard to the fill station and the blender if they are not adequately cleaned and compatible with oxygen.
The cleaning process removes any combustible materials that may have accumulated as a result of filling and using your tank, such as compressor oil, metal oxide particles, dirt, and debris from wear of o-rings and gaskets. These materials could act as kindling, and result in a catastrophic incident during the filling process. So be kind to your fill station operators and nitrox blenders, and have your enriched air tank oxygen cleaned when you have your annual visual inspection done.

In case you haven’t heard yet, the Palau Senate defeated Senate Bill 8-44 which would have opened Palau’s waters to commercial shark fishing, and at the United Nations on September 25th, President Johnson Toribiong of Palau declared the creation of the world's first National Shark Sanctuary and called for an international ban on shark finning. This was at least in part a response to the petition that was submitted by Shark Savers. Thanks go out to all of you who signed the petition. For more details, see www.sharksavers.org. Now we all should schedule a dive trip to Palau.

I logged my 1000th dive this past weekend, so I took the occasion of this milestone to pull out my old log books and review my diving career. It all began on a snowy November day at Gilboa Quarry. That is where I learned that 50oF water feels warm when the air temperature is 30oF. Then, just to prove that I hadn’t gotten any smarter, I took an ice diving course that winter and did the dives in a wetsuit. After that my dives were generally warmer and more interesting. Those 1000 dives include dives in all of the Great Lakes, several not so great lakes, and a couple rivers. And of course, I have logged a few trips to the Caribbean and tropical Pacific. It is hard to say which were my favorites. Some, of course were more fun than others, but they were all experiences that I treasure.
It was fun to go through the old log books, and recall the dives and the people who were there. I’m glad that I logged them all, not only for sentimental reasons, but also so I could do some statistics. (The engineer in me wouldn’t let me get away without doing some analysis.) I found that my average dive is a little over 35 minutes, and I have spent about 24 ½ days underwater not including the time spent in pool training and practice. On average, I have logged about 56 dives per year.
So now I am on to my next thousand, and looking forward to them all.

Safe diving to all,

Tom Rhoad

I had a chance to go on a dive charter on Lake Huron yesterday, and it was a beautiful day. The waves were about 1 foot, the sun was shining, and the visibility was good, about 40 feet. We dove on the Dunderberg, one of my favorite wrecks to explore. The Dunderberg, a three-masted schooner, was barely a year old when she sank in 1868, after being rammed by the steamer Empire State. Now she lies at a depth of about 150 feet in the cold waters of Lake Huron, just a few miles off shore near the tip of Michigan’s thumb. The wreck is remarkably well preserved, and the hull is intact except for the large gash in the starboard side near the stern where the Empire State hit her. The main attraction is the figurehead depicting an alligator or lizard, or maybe some imaginary animal. There is also ornate scrollwork carved in the boards leading to the anchors from the figurehead. As is typical in wooden shipwrecks, there are no cabins or structures left above the deck. Those get blown off as the ship sinks. The mast and rigging are still there, lying on the deck and off the port side. All of it is clearly visible despite the invasion of zebra mussels that are covering all if the Great Lakes shipwrecks.
Anyway, I enjoyed the dive despite the 42oF water temperature, and I enjoyed the time on the Lake. It was one of those days that make me appreciate what an incredible resource the Great Lakes is.

In the past couple months we’ve seen a lot of old, used gear come into the shop for service or just to be checked out. It seems that people are digging out their old scuba gear and selling it on-line or at a garage sale. There are some really good deals out there, but, as always, it is “buyers beware.” Those old aluminum scuba tanks may look tempting, but remember that many aluminum tanks manufactured before 1988 were made from an alloy that had a tendency to crack in the neck area (called “sustained load cracking”). These tanks may still be good, but require a close inspection of the thread area to assure that there are no cracks, and some fill stations will refuse to fill them regardless. The old steel tanks are usually the classic old steel 72s, and are generally OK, but watch out for rust on the inside and obsolete valves. There can be issues with older regulators, also. Some manufacturers have gone out of business or regulator models have been dropped, and we can no longer service their products. For example, Dacor regulators manufactured before 1999 are no longer supported by Dacor’s new owner (but you can trade them in for a discount on new Mares regulators). Tekna regulators are no longer serviceable, and there have been a number of “store brand” regulators sold over the years that are now unsupported. Older BCDs can sometimes be leaky as their bladders get brittle and seams fail.
So the bottom line is: know what you are buying, check out those bargains closely before you buy, and remember that this stuff is life support equipment and choose it accordingly. As always, you can call us with your questions, and we will do our best to give you good advice.


Safe Diving,

Aquatic Adventures Dive Team