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What is PADI?

The Professional Association of Diving Instructors (PADI) is a recreational diving membership and diver training organization founded in 1966.

PADI Certification and DSD 

Diving Instructors at CoolBlue  are PADI certified and hence issue PADI certifications. You can also sign up for the Discover Scuba Diving (DSD) option. For a full breakdown PADI courses  and activities, visit

What are our Dive Ratios?

For dive tours, our diver to Instructor/Divemaster ratio is 6:1. For  the DSD and certification courses it is 4:1.



What is a Fringing Reef?

This is the most  common type of  coral reef. It grows seaward directly from the shore, islets and pinnacles. They form borders along the shoreline and surrounding islands/islets.

What is a Platform Reef?

This is a coral reef which is built upward from the seafloor. They can be found at greater depths than other coral formations, and can also be a fair distance away from the main landmass. These reefs can form on a continental shelf as well as in the open ocean, in fact anywhere where the seabed rises close enough to the surface of the ocean to enable the growth of reef-forming corals

What is a Wall Dive?

In diving jargon, a 'wall' is basically an underwater cliff face. It would be best to think of it as a reef edge that runs vertically, from shallow to deep, dropping off suddenly into the depths of the ocean. Diving along this vertical reef edge is dubbed wall diving. They are attractive to divers as they offer a unique perspective, especially when they are teeming with coral and marine life. 

What is a Drift Dive?

Drift diving along with other types of specialty types of diving, can be explored in much more detail in the PADI Advanced Open Water Diver course.

For drift diving you are essentially dropped off at point A and picked up at point B and go with the currents along the reef tables and witness the show.

In mild current this style of diving can be very relaxing, as you mainly have to tune your buoyancy and go along for the ride; seldom using your fins for propulsion. In stronger currents this type of diving can be quite exciting and can even give you an adrenaline rush. 

In addition to this, currents, especially those that rise from the deep, carry nutrients which foster rich and abundant  marine life; they serve as a food delivery system to the lower levels of life in the sea. Corals can be seen wide open in a current as they take in nutrients. Small fish will come out of hiding to eat. Larger fish and pelagics are attracted by the increase in smaller fish. When you are doing a drift dive in a strong current, you can quite likely witness this buffet!

In Tobago, there are quite a few spectacular dive sites where you can experience this style of diving!






What is current?

The simplest definition for current is “water movement”. A mild current may barely affect your dive, a light to medium current could be enough to help you glide along the reef, or currents can be incredibly strong and therefore impact on how you conduct your dive. They are affected by various factors; large oceanic systems move constantly, whilst smaller local currents are affected by wind, water density, and tides.


When scuba divers refer to a “strong current”, it is the consistent fast movement of water in one specific direction. However, currents like to keep us on our toes; they can switch direction, push upwards or downwards, or change intensity at different points in your dive. You can also come across surge, which is more of a rolling-back-and-forth motion.

Tips for diving in current

Currents tend to get 'slacker' the deeper you go. If the currents are quite strong, you may be more comfortable closer to the reef table in a streamlined/trimmed position. When doing this, pay attention to your buoyancy though, as you don't want to damage the delicate corals! 

What is a Knot

This unit indicates the speed/strength of a current. It expresses this in Nautical mi/hr., with a Nautical mile being 1.15mi. To shed a bit of perspective, on land, the average person walks at about 3 mi/hr; this is approximately 2.6 knots.


Diver exhibiting good trim position

in a drift dive

What are the Difficulty Grades?

As divers (especially if recently certified) you may want to know which sites are appropriate for your level of experience and comfort.

The truth about this is, the best way to get the exact information you need to put your mind at ease, is to ask us directly. Ultimately, choosing a dive spot, weather you are a beginner or very experienced, essentially comes down to how comfortable you are in the water at that particular point in time. Your health, level of fitness and when your last dive was, should also all be critical factors to consider when making this decision.

Like any sport, there are varying difficulty levels for this activity. The guidelines below serve to provide a general idea on what to expect from the various dive sites we offer. Please keep in mind that the rating of a dive site can fluctuate depending on the physical conditions at the time of your time, i.e. visibility; strength of currents and surface conditions. It is therefore particularly important to appreciate the guidance and advice offered by your dive master/instructor at the time of your dive; your safety is their priority.


These would typically be dives on Fringing Reefs with gently sloping gradients. Your choices here would also include some shore entry dives. The descents would always be very controlled with a positive entry in sheltered areas; the ascents would also be very controlled and also in sheltered areas.  Current and surge activity on these dives would be non-existent to very slack. The maximum depth on these dives would be 18m/60ft.


These would also typically be dives on Fringing Reefs with some reef tables having slightly steeper gradients. Some of these sites (especially if visibility and surface conditions are not favorable) will be restricted to Advanced Open Water divers, or divers having at least 20 logged dives.

Descents/ascents could be in slightly more exposed areas. These can often be drift dives with mild current activity (up to 1 knot). Mild surge may also be encountered. The maximum depth on these dives may exceed 18m/60ft, but not more than 30m/100ft.


These can include dives on Fringing Reefs forming off of pinnacles in exposed areas with steep gradients. They also include Platform Reef dives, Wall Dives and Wreck dives. Descents/ascents are likely to be in exposed areas and a negative entry is sometimes required.

Depending on the conditions at the time, these dives can often be fast drift dives with current activity ranging from moderate (1-3 knots) - severe (3-5 knots). Moderate surge may also be encountered. The maximum depth on these dives would typically exceed 18m/60ft, but not more than 30m/100ft.



Nitrogen Narcosis

This is an alteration in consciousness which can occur while diving. It usually occurs on deeper dives (approaching 30m/100ft or more) but has been known to occur even at 20m/60ft and shallower. We can safely say that susceptibility to this condition varies from diver to diver and from dive to dive... even on the same day!

What causes it?

It is largely caused by the anesthetic effect of certain gases at high pressure. These gases have increased solubility into body tissues when diving at higher pressures at depth.

While diving you inhale compressed air from your tank. This air is under even more pressure the deeper you go. The oxygen and nitrogen in your blood and respiratory system is also under this pressure. This circumstance affects your central nervous system; the specific mechanisms that cause this to happen are still unclear.


If asked, a diver who has experienced this condition will most probably describe it a having a feeling of  tranquility and euphoria or being 'drunk'. Others can attain a false sense of security and mastery of the environment.

Other symptoms of this condition can include:

  • poor judgement

  • short-term memory loss

  • trouble concentrating

  • disorientation

  • reduced nerve and muscle function

  • hyper-focusing on a specific area

  • hallucinations

Who is prone to Nitrogen Narcosis?

As mentioned above, Narcosis can affect any diver at different depths in different ways. Research has shown however, that a diver will have a higher risk of developing nitrogen narcosis if  he/she:

  • consumes alcohol before diving

  • has anxiety

  • is fatigued

  • develops hypothermia before or during a dive

How to Stop Narcosis During a Dive?

This is an easy fix, simply slowly ascend a few meters/10-12 ft at a  time and the affects will wear off almost immediately... as you ascend the pressure decreases and the symptoms subside. To avoid its re-occurrence  just maintain a shallower dive profile. Its all about managing the situation properly. Your dive buddy or Dive Master will also be able to lend a helping hand or at least keep a watchful eye.

How Dangerous is Narcosis?

Narcosis isn’t dangerous in itself. However, how a diver reacts to it can cause problems.  When divers experience narcosis, their thinking process slows down, their judgement will become impaired and their co-ordination becomes clumsier. A more experienced diver will be cognizant of this and treat with it accordingly. 

Less experienced divers, especially if feeling a false sense of security and mastery of the environment, may have more of a tendency to not adhere to the basic safety guidelines of diving. This could include venturing too deep for too long,  or ascending too quickly.





What is DCI?

This is a term used to describe illnesses that are brought on by a reduction in the ambient pressure surrounding a body. This most commonly occurs when surfacing after a dive and not adhering to the standards and practices of safe diving, the main one being slow and controlled ascents. There are other risk factors which come into play as well. These are: 

  • Successive deep, long dives

  • Violating or approaching too closely the diving table limits

  • Cold water dives

  • Strenuous exercise at depth

  • Flying after diving

  • Holding your breath while diving, especially during an ascent

Other non-conclusive factors are:

  • Obesity

  • Dehydration

  • Strenuous exercise immediately after diving

  • Pre-existing conditions such as pulmonary disease

DCI encompasses two diseases;

  1. Decompression sickness (DCS)

  2. Arterial gas embolism (AGE)

Taking the above factors into consideration it would not be abnormal for one diver to suffer from DCI and not another who has followed the same dive profile. As such, evaluation of a diver suspected of having decompression illness must be made on a case-by-case basis with thorough evaluation of the diver's signs and symptoms and not just the divers dive profile.

What is the treatment for DCI?

For a suspected case of DCI, you must seek immediate medical guidance and attention.

The treatment for DCI is recompression at a Hyperbaric Chamber Facility. It is also critical for proper early management  of DCI. The patient has to be stabilized before arriving/on the way to the treatment facility.Early oxygen administration is paramount here and may reduce symptoms substantially, 

If  you are not successful making contact with your local treatment facility or medical professional you can contact the Divers Alert Network (DAN) for advice and guidance (DAN International Emergency Hotline: +1-919-684-9111). 

N.B. Delays in seeking treatment have a higher risk of residual symptoms. Over time, the initially reversible damage may become permanent. After a delay of 24 hours or more, treatment may become ineffective and symptoms may not respond to treatment. 

DCI Treatment Facilities in Trinidad & Tobago

Roxborough Hyperbaric Chamber Facility

Windward Rd, Roxborough, Tobago

open 24 hrs/day, 7days/week

Tel: 1 (868) 493 4973

Hyperbaric Treatment Centre Ltd

6-8 Broome Street, St.Clair
Port of Spain

open Mon-Fri, 8a.m. - 4 p.m.

Tel: 1 (868) 628-9261


DCS, commonly referred to as 'the bends'. It essentially results from inadequate decompression following exposure to increased pressure. Here nitrogen bubbles come out of solution during the regular respiratory process and enters  tissue, the bloodstream and joints. This causes local damage and pain.

When high levels of bubbles occur, complex reactions can take place in the body, usually in the spinal cord or brain. If great amounts of decompression are missed and large numbers of bubbles enter the venous bloodstream, congestive symptoms in the lung and circulatory shock can then occur.

Symptoms and signs of DCS usually appear within 15 minutes to 12 hours after surfacing. In more severe cases, symptoms may appear before surfacing or immediately afterwards. Delayed occurrence of symptoms is rare, but it does occur, especially if flying follows diving.  These include:

  • Unusual fatigue

  • Itchy skin

  • Blotchy skin rash

  • Pain in joints and/or muscles, usually in the arms, legs or torso

  • Dizziness, vertigo, ringing in the ears

  • Numbness and tingling sensations about the body which can be 'crackly' to touch

  • Shortness of breath

  • Difficulty urinating

  • Confusion, personality changes, bizarre behavior

  • Amnesia, tremors

  • Staggering

  • Coughing up bloody, frothy sputum

  • Collapse or unconsciousness​

Sometimes these symptoms remain mild and go away by themselves, but in more serious cases cases they increase in severity. 

What happens if DCS is left untreated?

In severe DCS cases, a permanent residual handicap may result. This can include bladder dysfunction, sexual dysfunction, muscular weakness and spinal cord complications. Untreated joint pains that subside are thought to cause small areas of bone damage called osteonecrosis; this may eventually lead to arthritis. 

AGE results from bubbles entering the lung circulation, traveling through the arteries and causing tissue damage by blocking blood flow at the small vessel level.

If a diver surfaces without exhaling, air trapped in the lungs expands on the ascent which can cause lung tissue to rupture and release gas bubbles into the arterial circulation; this is referred to as a pulmonary barotrauma. They are then distributed in body tissues in proportion to the level of blood flow.

The brain receives the highest proportion of blood flow and as such is the main organ where these bubbles can become lodged in small arteries and interrupt circulation. For this reason an AGE is deemed the more serious form of DCI.


What can induce an AGE?


  • A  fast, panicked ascent with the diver holding his/her breath

  • A normal ascent with the diver having a pre-existing pulmonary disease such as obstructive lung disease

In severe cases, a diver can surface unconscious. In less severe cases the diver may lose consciousness within 10 minutes of surfacing. In these cases, immediate emergency medical attention is required.  

Other symptoms in less severe cases are:

  • Sensations of tingling or numbness

  • Decreased sensation

  • Sensation of weakness without paralysis      Paralysis

  • Difficulty thinking or processing thoughts

  • Dizziness

  • Visual blurring

  • Chest pain

  • Disorientation

  • Bloody froth from mouth or nose

  • Convulsions

  • Cessation of breathing

  • Death

Sometimes symptoms may resolve spontaneously and the diver may contemplate not seeking treatment. As with untreated DCS, residual damage (to the brain) may occur, 

How to Prevent AGE?

Relax and breathe normally during ascent.

Get medical clearance prior to diving if you have a pre-exiting lung condition which may predispose you. This can include asthma, infections, cysts, tumors, scar tissue from surgery or obstructive lung disease.


Why to practice good buoyancy and have minimum contact with marine life?

At CoolBlue Diving we promote environmentally friendly diving. Key to this is minimum contact with the underwater life. To a great extent, this is achieved through proper buoyancy control. Not only is this good for the underwater environment, it also avoids you falling victim to unlikely injuries caused by marine life. Some of these are listed below.



Sea Urchins

Sea Urchins are small, spiny, globular animals between 3cm–10cm/1"-4" in diameter. They move slowly and are very sensitive to touch, light and movement. A Sea Urchin can even launch its spines forward as a defensive reaction to sensed movement.


If contact is made, the spines of this creature can inflict a painful wound. The spine fragments left behind can also lead to infection.



  • Immerse the affected area for 30-90 minutes in water as hot as the injured person can tolerate; repeat as necessary to control pain

  • Use tweezers to remove any large spines in the wound

  • Do not close the wound with tape or glue

  • Apply topical antibiotic ointment


Fire Corals

Fire corals are colonial marine organisms that exhibit physical characteristics similar to that of coral; they are not true corals. They appear in small brush-like growths on rocks and coral.


Contact with this organism can cause intense pain; itching; welts and blisters. Effects could last up to 2 weeks.



  • Rinse with seawater (fresh water will increase pain)

  • Apply topical acetic acid (vinegar) or isopropyl alcohol; this can inactivate the venom (toxin)

  • Remove any parts of the fire coral with tweezers or with tape after treating with acetic acid or isopropyl alcohol; this will help remove the toxins

  • Immobilize the extremity; movement may cause the toxin to spread

  • Apply hydrocortisone cream two to three times daily as needed for itching. Discontinue immediately if any signs of infection appear.

  • If no signs of allergic reaction are present, pain may be relieved with one to two tablets of acetaminophen (Tylenol) every 4 hours and/or one to two tablets of ibuprofen (Motrin, Advil) every 6-8 hours.


*A member  of the CoolBlue team will administer these first aid steps for this unlikely occurrence.For severe cases or if shortness of breath; swelling of the tongue, face, or throat; or other signs of a severe allergic reaction develops, we will need to seek further medical treatment.


Lionfish & Stonefish  

These fish belong to the Scorpion fish family. They have sharp spines coated with venomous mucus. Contact can cause moderate to severe neuro-toxin poisoning and intense pain follows. This peaks in 1 to 2 hours and could last up to 12 hours.

Redness, bruising, swelling, numbness, tingling, blisters or vesicles and tissue shedding at the wound site may also occur.

Severe reactions can include nausea, vomiting, abdominal cramps, tremors, abnormal heart rhythms, weakness, headache, diarrhea, shortness of breath, seizures, decreased blood pressure, fainting, paralysis and hallucinations.

  • Remove the victim from the water to prevent drowning

  • Immerse the wound for 30 to 90 minutes in water as hot as the poisoned person can tolerate; repeat as necessary to control pain

  • Use tweezers to remove any spines in the wound, using caution to not squeeze venom glands that may have broken off in the wound with the spine

  • Scrub the wound with soap and water; then flush the affected area with fresh water

  • Do not apply tape to close the wound as this may increase the risk of infection.

A member of the CoolBlue team will administer these first aid steps in the unlikely that event that contact is made.

In addition, patients may need a tetanus booster; this is usually recommended for all patients exposed to this type of poisoning. All cases of Scorpion fish poisoning require medical attention to ensure no foreign material remains in the wound and to provide symptomatic care as needed.


These are soft bodied, free-swimming aquatic animals with a gelatinous umbrella-shaped bell, with trailing tentacles. Contact with a jellyfish tentacle can trigger millions of nematocysts to pierce the skin and inject venom.

The venom of some species can cause adverse reactions in humans such as vomiting; lymph node swelling; muscle spasms and abdominal pain. Others may just cause mild itching.

  • Soak or rinse the area in vinegar (acetic acid) for 15-30 minutes to stop the nematocysts from releasing toxins. You can also rinse in sea water or isopropyl alcohol

  • Do not use fresh water to rub the area as this will cause continued toxin release

  • Apply ice or hot water

  • Wearing gloves, remove tentacles with a stick or a pair of tweezers

  • Apply shaving cream or a paste of baking soda to the area. Shave the area with a razor or credit card to remove any adherent nematocysts

  • Reapply vinegar or alcohol. The shaving cream or paste prevents nematocysts that have not been activated from releasing their toxin during removal with the razor.

  • Eye stings should be rinsed with a commercial saline solution like Artificial Tears; dab the skin around the eyes with a towel that has been soaked in vinegar. Do not place vinegar directly in the eyes.

  • Mouth stings should be treated with 1/4 strength vinegar. Gargle and spit out the solution. Do not drink or swallow the solution.

  • For pain, take acetaminophen (Tylenol) 325 mg 1-2 tablets every 4-6 hours for pain; or Ibuprofen (Motrin) or Aleve every 8 hours for pain.

  • CPR may be necessary for all stings if the person stops breathing and/or no longer has a pulse

A member of the CoolBlue team will administer these first aid steps. We will need to seek medical attention in the unlikely event of a severe case.

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