Frogfish - Bonaire

Quick post of a nice orange Frogfish perched on two branches of coral I managed to capture near the island of Klein Bonaire near Kralendijk, Bonaire, Netherlands Antilles.

If you look closely you can see the lure tucked back on his head. (Click picture for larger image)

When diving, Orange is the second color to loose resolution (remember the old adage for the colors of the Rainbow - "Roy G. Biv"). As you dive deeper, it is the same. The colors fade in sequence, red, orange, yellow, green, blue, indigo, violet.

A flashlight (or a camera strobe) will instantly restore the natural colors. Without a flash, this little guy has perfect camouflage and is almost impossible to detect.

The image below shows the same Frogfish without the benefit of a Camera strobe.

Sample SDI Pre- Dive Briefing

Dive Briefing

(Note - delete/shorten Briefing as necessary based on

Training and Conditions!!, to well - make it Brief!!)

Perform Accountability Check!!

Introduce Staff on Boat

Facilities at the Site
Boat Facilities
o Fire Extinguisher
o Remain seated while traveling & mooring
o Marine Radio
o GPS
o Fire Extinguisher
o First Aid Kit
o DAN Oxygen on-board – certified to use

Area in which the diving will occur
Mooring Line Location
History of Site & UW features
Silty Bottom conditions?
Describe the dive site
o Depth to bottom
o Visibility
o Temperature

Profile
Computer dive!!
_____ Max Depth (stay above Instructor/DM)
_____ Bottom Time

Monitor your gas supply – depletes fast at depth – at 99’, use 4x as much
Remember “Rule of Thirds”
First Diver to hit 1,000 PSI indicate to Instructor or DM by signaling
Back on Boat with 500 psi!
NO DECOMPRESSION DIVING – do not exceed NDL!!
Ascent Procedure – max safe rate is 30 feet/second
3-minute safety stop at 15 feet (10 – 20) mandatory - avoid crowding the line

_____ Surface Interval
_____ 2nd Dive Depth
_____ 2nd Dive Bottom Time

Entry and Exit Procedures
Exiting the Boat
o Carry fins to rear of boat, put on before exit
o Wait for DM OK to exit
o Hand on Mask and Regulator
o Hand on Gauges
o Giant Stride
o OK Sign to DM – clear from Boat
o Buddy Teams
o Swim to mooring line & descend when ready
o Wait at Mooring on Bottom for Instructor before proceeding
o Safety Check
Boarding the Boat
o Do not surface under ladder
o OK to DM after surfacing
o Leave Regulator in Mouth, and Mask on until on Boat
o Positive Buoyancy
o Ensure ladder is clear of divers
o Fins on/Fins Off
o DM will help you to your seat
o Bungee Tank
o (Begin prep for next dive & changeover tanks)

Buddy Team Assignments
Buddy Team Assignments – any diver without Buddy?
Buddy Check - Head to Toe
o Mask
o Air On
o Regulator & Alternate Air supply breathe freely
o All Buckles snapped
o Proper weighting.
o BC - Partially Inflated
o Gauges – Air Pressure
o Computer on – and set for proper Gas Mixture

Hazards
Nitrogen Narcosis - impairment
Caution surfacing
Boats in area
Propeller
Current
Surge

Emergency Procedures
If you feel stressed or tired during the dive, notify the Instructor, and turn the dive.
Surface signal – turn dive immediately
Lost Buddy procedures –1 minute search, then surface
While in water - Recall signal – banging on ladder
Problems on surface – get attention of DMAbandon ship

Ten Commandments for Dive Trips

(Adapted From a Hotel Lobby in St. Martin)

1. Divers shalt not expect to find things as they are at home, for thou hast left home to find things different.
2. Divers shalt not take anything too seriously for a carefree mind is the start of a good dive holiday.
3. Thou shalt not let the other divers get on thy nerves for thou hast paid good money to enjoy thyself.
4. Remember to take half the dive gear as thou thinkest and twice the money.
5. Know at all times where thy passport is for a diver without a passport is a diver without a country.
6. Remember that if divers had been expected to stay in one place we would have been created with roots.
7. Divers shalt not worry for he that worrieth hath no pleasure and few things are that fatal.
8. When in a strange land divers shall be prepared to do somewhat as its people do.
9. Divers shalt not judge the people of a country by a person who hath given thee trouble.
10. Remember thou art a guest in other lands and the diver that treats his host with respect shall be honored.

Dive Safe!

What is the best dive computer?

Another newby asking for help...

Hi everyone. I apologize if this is a redundant topic - I did a brief search, but didn't see any recent posts for such a basic question as mine. I'm a pretty new diver - I have about 40 dives under my belt. I have an extraordinarily busy work schedule, with little time to 'research' dive equipment, but i'm in the market for a good entry level type of computer that I could grow into for casual dive use (eg, for beginner to intermediate divers - I'm probably never going to do mixed gas diving or technical diving - if I do, i'll buy a new computer if needed). I was hoping that some of you may be able to narrow my search by listing 5 to 10 dive computers that would be worth looking into, preferably in the $300 dollar range (a bit more or less is okay). Thanks, in advance!

And my reply:

Some dive computers are more intuitive than others for different people. Therefore - it is hard to make a blanket statement about any computer that would best fit you. I would suggest stopping into your LDS and trying them out. Push the buttons & try the dive planning features. See what you like best (without spending hours reviewing the manuals - the manuals are kind of hard to take underwater anyway). Many of the manufacturers have on-line simulators where you can download and try out how the computers operate before you buy.

Nitrox compatibility up to 40% is almost a standard feature nowadays. Dive downloading (to your PC), deep stops and gas switching are becoming popular extra-cost options, along with wireless transmitters for gas pressure and air consumption
monitoring. Some of the features are out of your price range.

For me, I like the Suunto line. Not only is the information easy to understand, the way the computer works is very similar with all models. Also, the Suunto tissue saturation models are a little more conservative (err of the side of safety) than other manufacturers. Scuba Diving Magazine does regular comparisons of the aggressive vs. conservative nature of the different manufacturers, and I think you will find the results interesting, and this may sway your decision. Can't tell you the specific month/year of the last review - maybe somebody on the board can help. I think the Gekko, and the Vyper might be within striking range of your target price.

Hope this helps, and dive safe!

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!

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!

SDI IDC/IEC Instructor Course

Short post to reflect on the Scuba Diving International (SDI) Instructor Development Course (IDC) and Instructor Evaluation Course (IEC) to become an Open Water Scuba Instructor. A colleague and I went through the program together, and in total the Program took 7+ months. with about 80+ hours of class and pool time.

We averaged about 1 class session per week (of about 3 hours), with some weeks more, and some weeks less. The class sessions were very humbling, with the course being conducted by 2 SDI Instructor Trainers that I consider 2 of the best divers & Instructors I have known. The class presentations were sometimes scheduled topics, sometimes unannounced. Emphasis was placed on the SDI Presentation Outline, making sure that the topics and key points were clearly communicated, emphasised, and covered. In addition, special emphasis was placed on the "Big 3" of Advanced Training, Shop sponsored dive trips, and Gear Sales. I have made many management presentations throughout my career, but I will say that the SDI program was especially tough, and I learned a lot about myself, and gained additional confidence that can also be applied to business situations. The class also included the required swimming tests and skill demostrations, and very comprehensive written exam.

Now (finally!) as a certified SDI Instructor it reminds my of my younger days when I went through US Army Airborne School. By the time you got through the training, jumping out of a perfectly good Airplane at 1,500 feet at 130 mph was the easy part. The training is always designed to be harder to prepare you for the situations you may encounter.

I've conducted my first confined water classes with 10 Students with an experienced Instructor "Co-Instructing" with me. As indicated above, I found the experience easier (and less stressful) than the IDC/IEC, and also much more rewarding in the respect of seeing people "coming in off the street" complete the academic and Confined Water portion of the training and gain new skills and self-confidence. Many of the students in my first confined water (CW) class went to the lake this weekend for their Open Water (OW) training with another Instructor, and I look forward to feedback about their preparation in becoming "Certified Divers".

So - as a fledgling Instructor - I would encourage all divers in their quest for advanced training. I also look forward to teaching many more Confined Water and Open Water classes to develop my own methods - taking tips from many of the great Instructors I have worked with. By the way, I also picked up Instructor status for about 10 additional Specialties, such as Deep, Wreck, Navigation, etc.

If you think being a Divemaster or Instructor is in your future - go for it.

Dive Safe.

Long time gone

Has it been seven months? Where have I been? How about diving in Bonaire, and the beautiful Lakes of the Upstate of SC?

Main time consumer is that I have been going through the SDI Instructor IDC & IEC, and after many months, I think I can finally see the light at the end of the tunnel (or is it a train?). I intend to post more reflections on the experience after I have had a chance to fully reflect on the class.

Bottom line - never give up!

More to follow.

Dive Safe!

Lake Jocassee Water Temperature

Quick report from my dives yesterday at the Divers Ramp at Devil's Fork State Park, Lake Jocassee.

• Surface temps in the upper 70's/low 80's.
• Mild thermocline starting at about 20'
• Water temps at my max. depth of 111' at about 55 degrees F. Hood and gloves recommended (unless you really like ice cream headaches!).
• I wore a 7mm with a hooded vest, and was toasty warm.
• If you are planning to dive shallow (say less than 50'), you could probably get away without a hood and gloves - but that is a personal preference. Several people were in shorties.
• Dove fairly early yesterday morning, and not too many other divers. Visibility was stirred up as usual around the guidelines down to about 40 feet. Going beyond the fiberglass boat, Bones family, and past the Cattle Gate into the "Haunted Forest", the vis cleared up considerably. Carried my HID can light, but more for signaling than anything.

Hope you find this useful!

Dive Safe!

Simplified Gas Management for Deep Recreational Diving

Many excellent articles on this subject are available for Technical divers, but I find that many Recreational Courses do not present the basics of Gas Management to the Recreational Diver. The worst case scenario is that you encounter a major problem at deep recreational depths (in my definition between 60 and 130 feet) and find that you do not have a sufficient volume of gas for you and your Buddy to safely manage the problem and ascend to the surface - a potentially dangerous situation!

Given the physics of Boyle's Law, we know that as we dive deeper, our air consumption increases proportionately with depth. So how much gas should be reserved as contingency? Many times, divers are simply told to turn the dive at 1/2 the tank pressure without respect to depth, or the fact that many buddy teams may have different tank sizes. Turning the dive at 1/2 (or even 1/3) of starting tank pressure may be sufficient to a point, but as depths increase this method will most probably not provide a proper safety margin should an underwater emergency occur. It is your responsibility to determine your minimum gas requirements. This is why you are required to sign that Liability Waiver!

For this example, I am considering a body of water such as a Lake with no current, since current significantly changes the calculations and complexity of the situation.

From a high level, the steps should be as follows:

1. Calculate and monitor your Surface Air Consumption (SAC) Rate and Respiratory Minute Volume (RMV). Why? These factors tell you how your air consumption is doing both in psi per minute, and cubic feet per minute under normal - relaxed diving conditions.
2. Determine the stress level RMV for you and your Buddy. This should be a conservative value above your normal RMV.
3. Allow time for problem solving at depth - allow 1 minute at maximum depth
4. Allow time for ascent - assume max ascent rate of 30 feet per minute.
5. Allow time for deep stop - I allow 1 minute at 1/2 max depth.
6. Allow time for safety stop - 3 minutes at an assumed 20 feet.
7. Add the volumes above for each step. This is the Minimum Gas required for emergencies.

The above will determine the amount of gas (in cubic feet) that should be reserved (also referred to as "Rock Bottom") at which time you and your Buddy should start your ascent to the surface. This quantity of gas can then be converted to a pressure for convenience.

And now for the math:

To calculate your personal Surface Air Consumption (SAC) Rate - which expresses air consumption in psi/minute, or Respiratory Minute Volume (RMV) -which expresses the same factor in cubic feet per minute, I recommend to record over the course of several dives your rated tank volume, starting and ending air pressure, average dive depth and dive time. Many dive computers (especially hoseless with integrated pressure sensors) will log this data, and calculate these factors for you automatically. This data will provide you with valuable information about the efficiency of your air consumption - just like gas mileage on a car. With these values, use the following formulas for the calculation of values:

SAC Rate (psi/min) = ((Change in psi)/(Dive Time (min.)) /Avg. Depth (ATA)

RMV Rate (cu. ft./min) = SAC * (Rated Vol. of Tank (cu. ft.) / (Rated Pressure of Tank (psi.)

Why are these calculations necessary? It provides a basis for your personal air requirements. A real example (From one of my deep dives yesterday):

• Rated Tank Volume: 100 cu. ft.
• Rated Pressure: 3447 psi
• Actual Start Pressure: 3400 psi
• Actual End Pressure: 1800 psi
• Max Depth: 111 feet
• Average Depth: 56 feet
• Dive Time = 24 minutes

(By the way - I also carried a 30 cu.ft Pony Bottle with independent Regulator as Bailout)

Therefore:

• SAC Rate(psi/min) = ((Change in psi)/(Dive Time (min.)) /Avg. Depth (ATA)
• SAC Rate (psi/min) = ((3,400-1,800 psi)/(24 min.) /((56'/33')+1 ATA)
• SAC Rate = 24.72 psi/min.

and,

• RMV Rate (cu. ft./min) = SAC * (Rated Vol. of Tank (cu. ft.) / (Rated Pressure of Tank (psi.)
• RMV Rate (cu. ft./min) = 24.72 psi/min * (100 cu. ft.) / (3447 psi.)
• RMV Rate = 0.72 cu. ft./min

Referring to the original steps above, and for a theoretical dive to 120' deep:

1. My normal RMV is about 0.70 cu. ft./min. I personally assume a "Stressed RMV" of 1.0 cu.ft./min. You should evaluate this factor for yourself, and determine your own value. For Buddy and myself, a total RMV of 2.0 cu.ft./min. will be assumed. Note: This is the single most critical factor in this discussion. All other factors are mathematical calculations!!! Some divers use a Stressed RMV of 2.0 cu.ft./min. or higher.
2. Allow time for problem solving at depth - allow 1 minute at maximum depth. 120' = 4.64 ATA x 2.o cu. ft./min = 9.27 cu.ft.
3. Allow time for ascent - 120' - total ascent time = 120'/30'/min. = 4 minutes, average depth = 120'/2 (average depth) = 60 ft. = 2.82 ATA. Air for Ascent = 4 min. * 2.82 ATA * 2.0 cu.ft/min = 22.55 cu.ft.
4. Allow time for deep stop - 120'/2 = 60 ft = 2.82 ATA. Air for deep stop = 2.82 ATA * 2.0 cu.ft./min = 5.64 cu.ft.
5. Allow time for safety stop - 20' = 1.61 ATA * 3 minutes * 2.0 cu.ft./min = 9.64 cu.ft.
6. Finally, Adding all this up, you should get something like 47.09 cu.ft to satisfy the emergency gas requirements for you and your Buddy breathing off 1 tank.
7. Converting to pressure this would be (47.09 cu.ft./100 cu.ft.) * 3,447 psi = 1,623 psi. Assuming you had a full fill to start with, your turn pressure to meet the Rock Bottom Requirements would be 1,824 psi. (3,447 psi - 1,623 psi.). These pressures are often rounded up for ease of memory, and can be recorded on your slate.

If you and your buddy have different tank sizes, it is only step 7 above that is different. Minimum gas requirements are only a function of depth and your air consumption (RMV). This should be calculated for each diver, and communicated to each other before the dive. The first diver to reach this turn pressure should signal to the other diver to turn the dive. This turn signal must be non-negotiable! It is a fairly simple matter to take this data and prepare a table for various depths and tank sizes that can be laminated and carried to the Dive Site.

Hopefully this guide has been easy to follow. Gas Management should be a critical skill for the deep recreational diver. Additional equipment for deep recreational dives such as redundant regulators (via Pony or Bailout Bottles) should also be considered for an additional measure of safety.

(Note: for further reference, please click here)

Dive Safe!