Wednesday, April 08, 2009

Do I really need Advanced Open Water (AOW) Training?

Recent question on ScubaBoard:

"Do I really need AOW for diving with charters going to sites for depths below 60'?

Is it common practice to reject divers going for trips to sites deeper than 60' ? I have never encountered this problem so far but would like to know others' experience as I plan to do more charters this year. I do not care about the card I would rather do more dives but the only thing that concerns me is being rejected.

My Reply:

Not to get into a science lesson, but my $0.02:

Breathing compressed air at depth has 2 main negative effects. The first is of course is Nitrogen loading which dictates your time at depth, and the second is Nitrogen Narcosis. Many divers experience Narcosis at about 100+ feet, and diving with a training course will expose you to Narcosis under controlled conditions and allow you to see how you will react.

From Open Water training remember Boyle's Law. As you dive deeper, your air consumption becomes a multiple of your depth (in Atmospheres) times your Surface Air Consumption. This makes monitoring your air supply and consumption even more critical!

Finally - deep diving requires a greater reliance on your buddy and your gear, and starts bringing factors into play such as gear redundancy, self-rescue, and gas management.

A Deep Diver Specialty (with any of the fine agencies) allows you to gain the knowledge and experiences necessary in a controlled environment to handle these situations and understand the risks. It's not about the card.

As to the poster who related stories about Open Water checkout dives on the Mighty O (Aircraft Carrier Oriskany sunk off the coast of Pensacola, FL), many agencies - such as SDI - limit Open Water Training dives to a maximum depth of 60' (for many of the reasons noted above). I would not want to use this for a student's first Open Water dives with a hard bottom waaaay down at 200'+, and a new diver with less than perfect buoyancy!

I'd go for the Deep Diver training!





Sunday, April 05, 2009

Can I rent everything at first?

Recent Post on Scubaboard:

"Can I rent everything at first? My wife and I start our first scuba class in Minnesota next week and will be going to Cozumel first week of April for the open water certification dives. We have mask, fins and snorkels and have snorkeled in (off?) Coz. I've read numerous posts saying we should try many kinds of equipment before buying our own. And a number of posts that if you do own equipment, you should take it ion the trip rather than renting on location. My specific question - is there anything (apart from the mask) that we absolutely should buy ahead of time? I believe the fee for the open water dives includes equipment. I expect we'd have to pay a rental fee if we dive more after the certification dives. Thanks!"

My response:

many good points so far. here's my $0.02 for your first big dive trip in 3 major groupings:

Mandatory (take with you):

  • Mask, Fins, and Snorkel - always the first set of personal gear recommended!
  • Wrist Mounted Dive computer - tracks your personal dive profile and Nitrogen Loading. Essential for multi-day trips with multiple dive operators. Set your personal dive preferences, and know the features & dive planning capabilities!
  • Wrist mounted dive compass.
  • Safety Sausage & signaling device.
  • Mask defog
  • Mesh dive bag to haul your stuff!

Optional (Rent until you know what you want & can afford):

  • Reg Set (First Stage, Second Stage and Octo).
  • BC (often purchased at same time as reg set, and computer).
  • Exposure Protection that fits - falls in the priority here closely.
  • Lights (start with a small BC mounted, then add a primary). If planning to do night dives on your trip, move this item up to mandatory!
  • Knife/cutting device (EMT Shears work great)
  • Emergency Kit - first aid kit, O-rings, straps, tools, etc. (Hopefully your operator will have all you need - but you never know.)

Really Optional! (not practical for Travel):
  • Tanks - rent! (until you are ready to afford steel!)
  • Weights
  • Reel(s)
  • Spare Mask
  • Pony Bottle/Redundant Air Source - for deep dives

Hope this helps.

Dive Safe!