Posts Tagged ‘rebreather’

Missed the Varanger… Again

Sunday, September 12th, 2010

After years of trying, I still have not made it to the Varanger.   However this time we were close!

Besides the Varanger issue, I’ve been trying to get together with some fellow instructors to schedule some student dives in the proper depth range.   It’s been hit or miss over the last year, but we were finally able to coordinate schedules.   Unfortunately, none of my students were available.   It figures.   I’ve never been on the Atlantis before, so I just headed out to check out the boat and crew, and hopefully get in some fun dives.

NOAA was calling for rough seas around a front of storms coming through.  The front generated a fantastic sunrise, but the old “red sky in morning” told us NOAA bouncy castle with slide might be right this time.  We could see the front to the south, so we headed north to out run it.    This plan worked well.  We never saw more than 2 ft seas, and we had a fresh water rinse for our gear on the trip home.

The Atlantis is located right inside the Absecan Inlet with parking next to the AC Aquarium.   She’s a large comfortable boat with lots of deck space, and room inside for passengers and dry gear.   Geoff has been trying to get me down to AC to try it out.  I must say, I was impressed.

Shortly we arrived on the Southern Lillian.  The crew had a grapnel on the wreck quickly, and Geoff jumped in to secure it.  Once secure, divers started dropping in.  As usual, I was helping everyone in, hoping to hear a bottom report before dragging my camera into the water.  Geoff reported that below the thermocline, the clear surface water gave way to dark muddy bottom conditions.  Visibility was estimated at 5 ft at best.

With most fish out of season, I rolled in to look for scallops or lobster.   Geoff was right, below the thermocline the temp dropped to 47, and the vis made it difficult to even read gauges.  Once on the bottom I tied off and started the search.  I’ve been on this wreck several times, but in the current vis, I had no idea where I was.  I pulled out a few lobsters with eggs, and finally scored a couple legal ones.   Most of the fish darted away from my light as it approached.   There was one notable exception.  Off in the distance, I could see a large white object.   On closer inspection, it was one of the largest Tog I’ve ever seen.  It was not intimidated by my light or me.   As I approached within a few feet, it slowly swam over the top of the nearest deck plate, and disappeared.

Satisfied with my catch, I headed back to the line.  for some reason, there were large “clumps” of vegetation.   No one was sure what it was, but in some areas of the wreck it was piled up like tumbleweeds.  Reeling up the line involved pulling out wads of this stuff.   The thermocline at 70 ft felt great, and I could immediately see the boat, and the fact that it was raining.

Most divers went in for a second dive.   I opted for one long dive, and was happy with the harvest it produced.

Many of us slept on the trip home.   There are six bunks below, and lots of space inside to stretch out.   Our wet gear got a fresh water rinse on the way, and we still made it back to watch the rest of the game.

It was not the Varanger, but it was still a fun day of diving.

October on the Resor

Sunday, October 11th, 2009

It certainly has been difficult to get out diving this fall. However, the few times we were able sneak out, the diving was fantastic. This Sunday we headed out to the Resor with a jam packed boat. Clearing the inlet we had nearly flat seas, and just a breath of a breeze. With the early start, the sun was just rising. We all kept our fingers crossed that the conditions would hold, since NOAA was calling for the wind to pick up a bit in the afternoon.

By the time we reached the wreck, the sun was a bit higher in the sky, and the conditions were still flat. The surface water was a nice Caribbean blue. Dropping down the line it was clear that there was a good current to the east. This made going a bit slow, but we were soon tied in.

While working with the line, shadowy figures kept appearing in the distance. At first I thought the dogfish were back, but it turned out to be bluefish. We vendita gonfiabili saw them inshore last week. Now there was a school buzzing around us on the Resor. Ever few minutes a few of them would dart by. Down on the sand, there were large fluke and flounder almost side by side. Normally we see one or the other, but here the flounder were hunting while the fluke were resting. Both scurried off when approached. Large tog are always around this wreck, and this was no exception. I spotted a few small lobsters, and one good size one with eggs.

I was nearing my turn time when I spotted a nice new Danforth with a long chain. At least I was not going up empty handed. It turns out that the current and the wind were not aligned, and I spent my deco holding my reel in one hand (attached to the Danforth and lift bag) and the shot line in the other. I was just hoping other divers would not get caught in the line.

My hunting efforts had been thwarted, but many others came up with lobster, tog and some nice size pollack. There were various reports of giant lobsters, deep in the wreck, well out of reach. A few folks had ventured out into the sand for scallops, with varying degrees of success.

All in all it was a great day of diving with 30-40 ft of vis and 65 degrees top to bottom. The wind had picked up as we started to head in, but it was still a comfortable ride home.

Drama on the High seas.

Saturday, July 25th, 2009
The Lockness stopped by

Saturday, Divers Den North had a charter to the Stolt. Everybody loves this wreck. The drive out was spent weaving and dodging the flotilla of recreational boats. Apparently there was a fluke tournament, and the masses had turned out.

When we reached the Stolt, Terry jumped in to set the hook.  Watching him descend, it was obvious that surface vis looked much better than the week before.  However, when we pulled up a dragger had passed very close to the wreck.  This raised concerns about the piscina gonfiabile con scivolo vis on the bottom. Terry had us tied in quickly, and the pool was open.  As divers were rolling in, the Lockness arrived from Long Island, and asked to join us.  Before long they were tied in, with their boat just off our stern.  Captain Dan seems to know everyone.  We were soon exchanging stories of dives, trips, and artifacts.

Divers started returning with bags of scallops, bugs and mussels. A couple of nice tog came up also. From the reports the temperatures jumping castle had not changed much, but the visibility was just the opposite. of last week. It was clear on the surface, and only 10 feet or so on the wreck.

I rolled in with a student, and we headed for the bottom right along the break. The reports were accurate, the vis was bad, with some surge at the top of the wreck, and current past the hull. We did a quick tour of the break, then headed slowly up the super structure. We poked our heads in a few holes, but the vis was just as bad inside. One interesting observation was the number of scallops on top of the wreck, and on the flat surface of the superstructure.

The Coast Guard takes over the escort

While we were in the water, a boat in distress was reported in our area. We got underway quickly, and sped off to assist. Upon arrival, we could see that the boat was low in the water, but they had stopped taking on water. We escorted them toward shore until the Coast Guard arrived on scene. Nothing like a little drama on the high seas.

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.