Posts Tagged ‘scuba training’

What’s involved in SCUBA training?

Wednesday, January 14th, 2009

This is a another common question along with:  How do you learn to dive?  How long does it take?

There are several Internationally recognized SCUBA training agencies.  There are some differences in the classes, but they all have a similar elements.

Classroom:  Learning ranges from books, to multimedia, to Internet training, but each contains a degree of classroom participation.  Here an instructor can answer any questions, and emphasize safety points.  Often they will stress procedures that me more common in the local diving area.  Yes, there is a test.

Pool:  The first dive experience is in “confined water”, usually a pool. Here we learn to perform certain skills in a safe, controlled environment.  Once mastered we move on to Open Water.

Open Water:   This is usually a lake or quarry.  Here we practice the skills again, and get to swim around and enjoy the dives.   The final dives may be on a boat, depending on the local diving.

I like to think of the class as covering bouncy castle for sale two general areas:  First, how to plan and execute your dive, and second, how to safely handle any problems that may occur during a dive.

The Basic SCUBA class roughly takes 14 hours of classroom, 10 hours of pool, and 5 open water dives.

Once completed, it’s recommended that new divers stay shallow (less than 60 ft) until they feel comfortable with the skills they have learned.  Then they can take additional training to learn the skills necessary to go deeper.

How deep can you dive on SCUBA?

Wednesday, January 14th, 2009

When people first hear about SCUBA diving, many ask this question.   My standard response is “to the bottom”.   While I am joking a bit, unless you’re doing a wall dive, this is usually the case.

Part of the answer depends on the location of the dive: off the coast of New Jersey, the bottom slopes gently for the first 30-50 miles.   Shortly after this we hit the Continental shelf, commonly called the Canyon.   Here the depth drops sharply to several thousand feet.   Obviously our diving is on the gently sloping bottom.

About 3 miles off the beach, the depth averages about 60ft.  After 20-30 miles, there are some great wrecks in 130 ft.   The bottom slope does vary from place to place.   There is narrow trough cut by the Hudson river commonly called the Mud Hole. Inflatable Water Slide It is deeper than the surrounding area, but the outflow of the river makes the conditions more challenging.

The rest of the answer depends on the diver’s experience and training:

Novice divers should stay shallower than 60ft, until they develop the skills and comfort in the water necessary to go deeper.

Advanced divers go between 60 and 130 ft.  At this point they carry additional safety equipment necessary to perform these dives.

Technical divers go beyond the 130 ft range down, sometimes in excess of 300 ft. These divers have spent years training and practicing for these dives.  They carry redundant gear and practice techniques to survive equipment failures.   Many famous shipwrecks are in this range: the Andrea Doria, the U-869, the Black Sunday wrecks including the S.S. Carolina.  These all fall in this range of technical dives.

How deep do I personally go?  Well, I teach Technical Divers.  While I enjoy spearfishing and photography in the 50-130 range, we can often be found diving in the 180-250 range.

What is a Rebreather?

Tuesday, January 13th, 2009

Many people see my dive gear, and ask “What newfangled contraptions is that”? Ok, maybe they don’t use the word “newfangled”, but you get the point. I dive a Closed Circuit Rebreather (aka CCR). While people think of these as “new”, they actually predate the gear we consider standard SCUBA (also called Open Circuit or OC).

History: Early rebreathers were used not for diving, but for escape. Mines and Submarines both presented situations where a compact breathing device was needed to allow crews to escape to safety. Theses were developed back in the early 1900, and produced in quantity by 1910. Open Circuit SCUBA was not commercially available until the mid 1940s.

How do they work: Let’s start with a quick review of metabolism. Our cells take in food and Oxygen (O2). These are combined to produce energy, but have a toxic byproduct of Carbon Dioxide (CO2). Our Cardiopulmonary system takes some of the O2 from the air we breath, and distributes it to our cells. At the same time it takes the CO2 generated bouncy castle for sale by our cells, and releases it into the air that we exhale. The O2 and CO2 exchanged by our lungs is actually a small percentage of the volume of gas that we breath (about 3%-5%).

On Open Circuit, when a diver inhales, the regulator provides the diver with gas (usually air) at same pressure as the surrounding water. When we exhale, the gas is vented out into the water producing the column of bubbles associated with diving.

When a CCR diver exhales, the gas is vented into a flexible chamber called a counter lung. Within the Rebreather, O2 is added back into the gas, and it is passed through a “scrubber” which removes the CO2. We then inhale the same gas which again contains the proper O2 percentage.

With OC 95% of the gas we exhale has not been affected by our respiration. It is not used. It is wasted. On CCR, this 95% is recycled, cleaned of CO2, enriched with O2, and breathed again. This allows us to make use of smaller tanks, as our O2 consumption does not change with depth.

The Wreck of the Delaware – August 18th by Lee Letwin

Thursday, August 16th, 2007

by Lee Letwin:

When we arrived at Clark’s Landing Marina at 6:30 AM, the wind was blowing from the west and we knew we were not going to the Algol, 20 miles offshore. Captain Dan Bartone of the Independence II figured the Pinta was a better choice.

Leaving Manasquan Inlet and heading north, the seas were surprisingly calm but after only 15 minutes we started to get beat up and decided to turn around and head south back to the wreck of the Delaware. The Delaware was built in Philadelphia. She was built as a freighter but during the Spanish -American War was refitted to carry passengers as most of the passenger liners were being used to carry troops. In July of 1898 she left her berth on the East River and was heading to Charleston and Jacksonville. Ten miles out to sea and east of Barnegat she caught fire. All 66 crew and passengers got off safely and were rescued. The wreck, burnt to the waterline, sank two miles offshore just south of Point Pleasant while being towed back to New York by a salvage tug.

All the divers aboard the Independence II did two dives on the Delaware and we all had a great day on the water despite difficult conditions. Our crew included Captain Dan, with Dave Oldham and Bill Trent working as crew. Dave tied us into the wreck wrapping the chain on the shot line solidly around a huge chunk of metal at the bow section of the wreck. There was little chance of pulling off the wreck with Dave’s tie-in despite the conditions. Inflatable Water Slide In fact, Captain Dan sent a line to a second dive boat that showed up after us (the advantage of us being on a fast dive boat) and the two boats held tight. Bill Trent played host to everyone and prepared lunch, which was provided as always by Adventure Scuba.

While unloading our gear we talked to the crew of another dive boat docked at the same marina. They had tied into a barge, did one dive and during their surface interval while being tossed about in the waves their anchor line parted. At that point they called it a day.

Its August, and its friken Cold! SS Carolina trip aboard the Independence II

Wednesday, August 1st, 2007

The Independence II made a run out the SS Carolina early Sunday morning. The plan was to stay overnight. To make a long story short, NOAA’s favorable forecast on Saturday night, was revised when we got out there. This cut our trip short, but we still got in some good dives.

Upon arrival, Captain Dan circled the wreck a few times as his depth finder readings did not look right to him. Bill and I jumped in to find the line right beside the wreck, but the wreck didn’t look right. Over the winter, the wreck has collapsed. I recall the starboard side standing some 20-30 ft off the bottom. Now it lay almost flat. Bill was much more familiar with the wreck, and was taken back by what he saw. I guess this explains why Capt Dan was circling.Inflatable Water Slide Bill was unable to find his favorite tie-in spot, so we grabbed the closest spot that looked good. One Ling cod was either very interested in what we were doing, or very pissed that we were digging in his hole. Either way he was never more than a few inches from us during the operation.

Vis on the bottom was a clear 50ft, but dark. We tied off a our beacons. Bill signaled “let’s go swimming”, and off we went. Before long we saw some china in the sand, and started to sift through them. It turned out to be mostly shards, but Bill was able to pull out a small ash tray. I had my hands on a large piece of porcelain, but was unable to get it out from under the decking. I was not sure what it was, but it was big, and the hole I was working in was too small for it to move. My planned bottom time was running short, so I signaled Bill and headed back to the line.

Looking at my computer during the ascent, I noticed something I hadn’t before. Its 42 degrees! It’s August, how can it be 42 degrees? That can’t be right, check the backup. Yup, 42 degrees! I could still see the beacons at the first deco stops start at 160, but the thermocline starts back at 50 ft. This was going to be friken COLD. There was little to no current on the line, but the cold started to get really bad. Our work load had prevented us from feeling it on the bottom, but now it started to set in. My body was warm enough, but at that depth, Neoprene gloves lose most of their insulation. Mine are 7 mil, but just looking at them, I can tell they are compressed.

At 70 ft the temp jumped up to 44, and I can actually say it felt good. At this point I was in the surface water which had to be 100+ ft of visibility. I could see Bill’s bubbles rising out of the cloudy layers below. At 50 ft the temp rose to 52 degrees, then at 30 it rose to 78. Now I’m sweating in my suit, but it felt much better. I was a little startled when a large Mula-mula swam right by me on the line. He looked at me for a moment, then swam toward Bill. Due to the cold and workload, I stayed a few extra minutes at the 20 ft stop. I could see Bill as he passed through the thermocline some 70 ft away.

On the surface the seas had turned to 4-6, and the forecast was to get worse tonight. Some of the other divers had passed me on the line. When Bill surface, he and Captain Dan discussed the changes in the wreck at length. Dan geared up and went in. The other passengers came up commenting on the cold. Discussions of numb fingers, and cutting bottom time short. Everyone mentioned the change in the wreck. There were descriptions of large lobsters, but no one wanted to grab them with their cold hands. I guess if they had delayed their dive until we surfaced, they could have switched to dry gloves. Dan had checked out some spots of interest, and came up with a brass shirt hanger.

Other than the cold, the conditions had been fantastic! When I jumped in to pull, the sun was now higher in the sky, and the wreck came into view shortly after the beacon. I didn’t really need my light. If the surface conditions were better, I’d love to have gotten more dives in. This is a great wreck with lots to see.