The ocean is full of undiscovered depths, shrouded in mystery. Her deep bosom reveals surprising historic artefacts and bountiful natural ecosystems. The Sri Lanka Navy is now operating her first dedicated diving vessel named Alpha-521.
This vessel with deep sea endurance was gifted from France, when she was a merchant vessel. Subsequently, outfitted as per naval patrolling requirements she is now transformed into a deep sea diving platform. The ocean has captivated us for centuries. It is this quest for exploration which sent mariners sailing across the globe. Yet, beneath the deep blue waters is another whole spectrum of discovery: one that can be witnessed only by calculated diving. It takes intense training and remarkable endurance to complete an underwater dive. This is one area in which the officers and sailors display their daring prowess. Civilians dive for pleasure in coral reefs, but the task of the Navy diver is very different and laden with risk.
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| Divers in action |
The Navy Diving School in Trincomalee is the only one of its kind in our country and I was privileged to visit this school. Its history dates back to July 1991.The present officer in charge of the school is Lieutenant Commander K.D.R.S. Dissanayake. These officers explained to me that all prospective sailors who want to undergo diver training must appear for an aptitude test, swimming test and PT test. Priority is placed on swimming. The stages of training are classified as Clearance Diver (CD) 1, 2 and 3. The initial course is carried out for 12 weeks. Just across the school is the vast blue ocean where practical diving classes take place. Divers are taught about salvage operations, underwater clearance, life saving, recovery of bodies, ship hull inspection (during the period of war, the enemy could place limpet mines that stick to the bottom of the ship by magnet), assist in underwater ship repairs and combat diving which includes reconnaissance and demolition. The trained diver also has the ability to carry a weapon and shoot from the water when required.
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| World War II propeller at Navy Headquarters |
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| All set to go |
Each of the three stages of learning lasts 26 weeks. In stages 3 and 2, sailors learn to dive up to 130 feet. Subsequently, in stage 1, they are encouragingly pushed to go up to 180 feet. Every diver must strive to maintain positive buoyancy. The wet suit, face mask and fins complete the outfit along with the 12.5 kg oxygen tank which facilitates the underwater mission. Surprisingly the ocean has its own natural threats in the form of deadly moray eels and lionfish that deliver a painful bite. A Lieutenant Commander added, “Safety on an assignment is important. “No Buddy- No Dive”, this means we always send a diver with another diver. Each man must look out for the other, as the sea has many hazards. Divers can get entangled in fishing nets and ropes. The knife is a key part of the sailor’s diving uniform. It can save your life at 180 feet.” As the sun joyfully spread its rays we went to the pier where a team was about to ‘cast off’ on a routine task. The dive Petty Officer gave a briefing to the men and we boarded a craft.
Another sailor stood by at the pier with the BR2806, an international dive manual which must be kept at all times. Upon reaching their location they hoisted the blue and white Alpha flag which is an international visual sign that divers are entering the sea. The four divers were ready to slide into the water with another diver on standby. The Navy divers are attached to a lifeline by which they communicate to the Dive Master. There is a system of pulls and tugs using the rope which sends out signals to the boat. Having completed the search, the divers climbed aboard and headed back to the pier. Once we reached the shore the divers had to wash their wet suits in fresh water and replenish the oxygen tanks. Every diver must take the annual chamber test calibrated to 55 metres. The conditions at sea are inconsistent and divers will be exposed to danger. Lack of oxygen created by various causes can make a diver paralysed. The Sri Lanka Navy has the only recompression chamber in Sri Lanka. This is a complex and unique machine which can treat 10 persons at a time. Installed from Germany in 1987, the chamber has saved many civilian lives by systematically treating them with fresh oxygen, after they were rescued at sea. Symptoms of underwater illnesses include, rash-like spots, numb feeling, twitching, nausea and loss of balance. At stage 2, every second counts and the victim must be rushed to the chamber as soon as possible. Every branch of the Navy was engaged in their duties during the war, on sea and land. The divers have provided a silent service during the war. They searched and secured the areas surrounding large naval vessels and did routine checks at main harbours. In peacetime, they helped to recover many dead bodies from lakes and rivers. During the aftermath of the 2004 Tsunami, they helped immensely in salvage operations to clear the approach ways of many harbours. The Navy Diving School, Trincomalee continues to train members of the Army, Air Force and Naval SBS teams in diving.
Onboard Alpha-521
I boarded the vessel and was duly greeted by the Quarter Master. The ship was different from the other combat Offshore Patrol Vessels I had previously visited. The Executive Officer explained, “This vessel is unique as she is the launching platform for our divers. Usually, there are divers attached to shore units. Now with this vessel, we can sail into the deep sea and take part in adventurous diving operations. Alpha-521 has a displacement of 592 tonnes with a sailing speed of 10 knots. Her sea endurance is almost 12 days. We have a crew of 81 men including nine officers.” She had made a successful salvage of a 10-tonne propeller, which had once belonged to a merchant ship during the Second World War. We walked into the wheelhouse on level four, where radars and echo sounders were in operation. From here the ocean view was stunning. The vessel is 54 metres long and 11 metres wide. She is commanded by Commander H.B.H. Deeshana.
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| Wheelhouse |
Diving officers and sailors operate in two certified categories – CDO (Clearance Diving Officer) who has the capacity to descend up to 55 metres underwater and SDO (Ship Diving Officer) who can venture 30 metres underwater. A Clearance Diving Officer (CDO) attached to Alpha-521 explained, “A Navy diver has an important task on entering the deep sea. Divers could get entangled in fishing nets and ropes. Before a diving expedition, there is an investigation team that launches from this vessel by boat to examine the designated sea area. We calculate the depth at which the diver would have to descend. The assigned officer or sailor has his meal six hours before the dive. He must be fully alert.”
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| Divers at work |
A few of the men recollected their experience of the first major salvage diving expedition that took place two nautical miles off the Little Basses area. A Sub-Lieutenant SDO explained, “Prior to this expedition our Officer in Charge made the first visit by small boat, our target was to locate and drag a 10-tonne propeller from the sea bed. The entire ship’s crew was excited and busy that morning. Ropes and cables were positioned. We had planned to lift the massive propeller using a system of airbags. We have airbags that can lift and float – with a capacity of one tonne, three tonnes, five tonnes and 10 tonnes. In this operation, we used two of the three-tonne airbags and one five tonne airbag. We managed to tow the heavy propeller to the Port of Hambantota and subsequently brought this historic relic to SLNS Rangalla in Colombo where it was hoisted by a crane.”
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| Clearance dive |
We walked to the rear of the ship from where divers entered the water. The temperature of the seawater is a vital element that impacts diving capability. Along with the fins, face mask, buoyancy device and two oxygen tanks he entered the water with a weight of 16 kilogrammes. The tanks provide him with air for almost 30 minutes. Divers must focus on how long they have been underwater and ascend carefully back to the ship. Normally, the ascent rate is 10 metres per minute for divers operating deeper than 20 feet. Ascent rates must be monitored to prevent the supersaturation of tissues which causes bubbles to build up. Alpha-521 maintains her own security at sea; she is fitted with guns and anti aircraft armament. We walked below the deck to see the crew quarters. The sailors were engaged in their daily sea routine. This vessel is powered by a Duwant turbine that generates 2,000 horse power. She has two anchors weighing 450 kg each. When not engaged in diving missions, Alpha-521 engages in naval patrols.
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| Underwater repair |
