This list of skills and notes is meant to better prepare you for the course dives so you get the most from your in-water time. These skills will be briefed and debriefed as part of the course, but reading them here will set you up for the most success. This list isn’t inclusive to all skill in the course, nor it is a replacement for the standards.

Predive checks and procedures are where we catch mistakes. We never want to dive with known problems.

House Check

Before you leave the house or hotel, physically check to make sure everything is packed. Double check your charging station to make sure you’re not leaving batteries behind. Check the dryer for undergarments and the drying rack for drysuits. Make sure tanks are loaded, analyzed, and full. 

Boat Check

Get everything out of the car and onto the boat. The fewer trips and bags, the better. Set up your station so it’s clean and organized for yourself and others around you. Ensure you have everything – and it works – before the boat leaves. There are no dive centers in the ocean.

  • Cylinders analyzed, labeled, gauged and the gas is appropriate for the dive depth
  • Regulators pressurized and breathed from
  • Wing is pressure tested
  • Gases programed into computer
  • Computer/light batteries
  • Any applicable notes/plans on wetnotes/slates
  • Team is comfortable with dive plan.

For boat diving efficiency I suggest a maximum of:

  • Dive bag or crate – fins, wetsuit, save a dive kit, accessories. Other containers can fit inside here.
  • Doubles with wing and harness
  • Deco cylinder(s)
  • Drybag with water bottle and personal gear.

Prejump Check

Open your valves and double check them, ensure your computer(s) are on. Listen to the crew to get your bearing on current, location, etc. If you’re unsure, ask. Take any notes needed on your wrist slate. Before splashing, check with the team that they have done the same. Look behind you after you stand to ensure nothing is on the bench/floor that you need. 

S-Drill

A proper s-drill is an often overlooked but crucial aspect of any deco dive. We ensure that everything is working at a shallow depth – if it doesn’t work at 15ft then 100ft probably won’t help. The s-drill will give you confidence everything is working and give you a moment to catch your breath if you got hot in your wetsuit on the boat. The s-drill is the best place to call a dive, but sometimes the “dive pressure” makes it the hardest place to call a dive.

Self checks

  • Regs work
  • Valves are open
  • Computers set to the proper gas
  • Pocket inventory
  • SMB is still there and stowed

Hot Drop

When hotdropping you must enter as a team and descend quickly so we don’t miss the wreck. The team should enter at as close to the same time as possible. Get negatively buoyant and begin the descent doing some self checks along the way. As you pass ~5ft test your inflator, do the team bubble checks and ensure long hoses are free. This should be done in a controlled manner, take a few moments, and very minorly arrest the descent. Continue the descent and orient yourself to the compass/current.

Descent Line

When tied into the wreck, meet the team between 15-20ft. If there is a strong current and there are 2+ members of the team you will have to split the team checks up, but as long as one team member verifies the check then you can continue.

Bottom Check

After a descent, especially a hotdrop, it’s common to be perceptually narrowed when you arrive to the wreck. S-drills will mitigate that, but it will happen. Having a prescribed “bottom check” should trigger you to widen that perception.

  • Neutral buoyancy
  • Orient yourself to the site – depth, compass, wreck features, etc
  • Methodical breathing
  • If needed, hide from the current
  • Ask teammates “ok?”

Valve Drill

You must be able to hover at a fixed depth and manipulate your valves. For this drill we will run through a typical diagnosis shutdown and manipulate all 3 valves (2 in sidemount). If you have trouble reaching your valves then we should look at configuration changes that accommodate reaching your valves.

Air Share

We will simulate an out of gas emergency at depth.

  • Deploy primary regulator and swap to backup
  • Control diver and deliver regulator
  • Keep control and begin ascent

SMB Deployment

You need to be proficient at deploying an SMB in an efficient manner that doesn’t hinder your deco profile. Having the rigging ready to be deployed quickly is a big help. I prefer to have the reel and SMB connected at the start of the dive. If you’re going to connect the two at depth then utilize metal rings and/or snaps to make it most efficient. There are 2 purposes to an SMB on a drift dive. One is to give a visual reference to the divers, the other is alerting the boat to your location. Different areas have specific protocols with how many SMBs are to be blown per team.

  • Become neutrally buoyant – look at your computer
  • Deploy the SMB and line
  • Add enough gas so the SMB becomes full at the surface.
    • Too much gas might blow up the bag, take you up with it, etc.
    • Too little gas won’t be visible to the boat.
    • It’s not an exact measurement, but think about 1/4, 1/3 full, etc.
  • Begin your ascent as the bag goes to the surface
    • If we’re at 150ft we don’t want to sit and rack up deco watching a bag go up  – plus it’s just more line to reel up.
  • Be slightly negative on the bag while doing deco.
    • This keeps the bag erect and above us.
    • If the current takes the bag too far away there’s a higher chance it will get tangled in another bag, boat, etc
    • Slightly negative accomplishes these things – don’t try and dump your BC and hang on the bag.

Bottle/Gear Management

We will work with your deco cylinder a lot to develop muscle memory. To start, we will drop it, swim in a circle and pick it back up. This isn’t a realistic practice at depth for most deco dives, but it gives up practice manipulating the clips and buoyancy. If we jumped in on accident with the cylinder clipped incorrectly we need the ability to unclip it and fix it. This skill gives us the confidence for that. We should be able to efficiently don/doff our deco cylinders.

We will unclip and stow our SMB, backup SMB, and deploy and use our backup mask. This gets us comfortable with all the functions of our gear and gives us a better ability to problem solve. For example, your SMB comes unfurled on descent. The ability to grab and fix it is very crucial.

Gas switch

Gas switches are one of the most important in-water skills for deco divers. Using a team methodology to switch gases helps ensure we’re at the right depth and using the right gas. It mitigates a lot of risk.

  • Realize the stop before that you have a gas switch coming up.
  • Get to switch depth.
  • Signal the switch to your teammate. Have them check the markings.
  • Check the analysis label.
  • Pressurize the cylinder, deploy and orient the hose.
  • Check your depth and get the affirmative signal from your buddy.
  • Swap regs, swap your computer.
  • Repeat the process for your buddy.

This entire process only takes a few moments. It’s important to keep control of your buoyancy before, during and after the gas switch.

Breath hold swim

You will do a breath hold swim along a line that is a specified length. Nothing really to note here.

Buddy Tow

Assisting teammates, at the surface or underwater, with doubles and deco bottles is different than the single tank world. You will tow your buddy in both locations.

BCD failures

We will simulate a stuck power inflator.

  • Raise he deflator above your head to dump gas
  • Disconnect the LPI hose
  • Manually inflate to recover buoyancy

SMB Failures

We will have a backup SMB and line to use in the event of an SMB failure. Depending on the type of failure you can use the backup SMB independently or clip it to the same line as the primary SMB.

If you accidently drop your reel/spool during deco you can use a spare double ender as a weight to retrieve the reel/spool.

  • Clip the double ender to the line.
  • Use a finger to hold the free end up.
  • Allow the clip to fall down the line.
  • The reel/spool with end up in your hand and you can spool up the line to get your double ender.

Decompression Cylinder Failures

After completing deco we will practice sharing a single deco regulator between 2 divers – buddy breathing. The mantra here is “breathe, breathe, pass”.

We will also practice fluttering the valve and diagnosing DIN fitting problems.

Decompression Failures

We will simulate staying too long, missing a deco stop, losing decompression gas and other decompression failures.