Friday, 13 May 2022

Rex I. De Silva's diving history





Started spearfishing around 1956

Started SCUBA diving around 1958                 

 

Some activities as a commercial diver (from 1968 to 1984).

Qualified for Colombo Port Commission Commercial Divers’ Licence in 1968.

Chief diver: Mobile Marine Engineering Company, Colombo 1968 – 1974.

Manager Underwater Division: Premier Engineers, Colombo 1974 – 1986.


Removal of marine fouling from 44 cargo vessels including the Supertanker M/t. “San Juan Vanguard” (165,000 tons) - the largest vessel to dock in Colombo Harbour at the time -  using Hydraulic underwater hull-cleaning equipment. 

Stern tube sealing of several vessels in the Port of Colombo

Repaired the damaged underwater section of the hull of M/v “Pulawy” (20,000 tons) preventing it from sinking in Colombo Harbour.

Underwater repairs to Japanese HOKO fishing company’s fleet of vessels in the Maldives in the 1970s.

Used oxy-arc underwater cutting equipment in salvaging cargo of mining equipment from the “Wombat” sunk off Nilweli Point.

Refloated trawler “Maple Leaf” sunk in Colombo Harbour.

Recovered main anchor of M/v. “Drachenfels” (30,000 tons) lost in silt in Colombo Harbour.

Underwater sealing of the scour gate and main outlet at Hasalaka tank (reservoir).

Underwater sealing of main outlet of Maduru Oya reservoir.

Annual removal of underwater obstructions from the main intakes at Kelanitissa power plant (1970s).

Search for and Recovery of drowned corpses.

Underwater search and recovery operations.

Training of individuals for commercial diving operations.

Numerous other diving and salvage operations. 

Sport Diving

Honorary Secretary and Spearfishing Captain of the “Reefcombers of Ceylon” diving club in the 1960s and '70s. 

Began underwater photography in   November 1967.

Spearfishing Captain of Kinross Swimming & Life Saving Club 1974.

Largest fish speared 115 lb Ray.

In 1970s held Reefcombers’ SCUBA depth record at 240 feet in Trincomalee submarine canyon. 

Scientific activities

Researched sharks and marine life since 1968. Documented 22 species of sharks which were previously not recorded from Sri Lanka.

Conducted 13 year landmark study on seabird migration.

Author of 120 peer-reviewed scientific papers, book chapters and other publications on Sri Lankan marine life.

Author of THE SHARKS OF SRI LANKA 2015.

Currently writing a “History of Diving in Sri Lanka” 

 

Other:


Logged an estimated 8,000 - 10,000 dives on both commercial operations and sport diving from 1956 to 2020.


Listed in ‘Who’s who of Sri Lanka’ (volume II).

 

Other Interests and activities:


Observational astronomer. Former (volunteer) lunar occultations observer for the United States Naval

Observatory (USNO) Station reference SXT94. Current observer/photographer of solar activity.


Fellow of the Linnean Socirty of London (FLS). 


Member of the Institute of Biology Sri Lanka, (MIBiol


Holder of advanced Black-belt degree in Shotokan Karate and holder of Master Instructor’s certification (SHIHAN) in martial arts.


Comments

·         “I have known Rex I De Silva for over two decades and admire his work and accomplishments in underwater exploration, wildlife and astronomy”.                                         Sir Arthur C. Clarke, Chancellor University of Moratuwa. 29 September 2001. 

·         “Mr. Rex De Silva, ‘Renaissance Man’, Naturalist, Environmentalist, Deep Sea Diver, Birder, Martial Arts expert and Scholar is as unusual as they come”.                                          Vidya Jyoti Ashley de Vos, President of the Wildlife and Nature  Protection   Society of Sri Lanka (1999-2000). 8th October 2001.  

·      “[Rex De Silva] is a person with an excellent knowledge of the ocean, land and sky”.                 Professor Sarath Kotagama, University of Colombo.                                                                                                                 


Awards

     Abacus Institute:  Honorary Diploma for “Outstanding contributions in the field of Environmental Protection”.


Marine Conservation Conference 2013: Award for an outstanding contribution “For years of devotion to the marine environment and its study, especially the sharks of Sri Lanka”.


   Rotary Vocational Service Award:For exemplary service and dedication in shark research and marine biology in Sri Lanka”. 


Declared an INTERNATIONAL LEGEND OF DIVING by the Legends of Diving Organisation (USA) in 2006.  


           










 

Tuesday, 5 October 2021

An Album of Sunspot Images

ALL IMAGES © Rex I De Silva







Transit of Venus




The Bear Claw Sunspot


Annular Eclipse 1


Annular Eclipse 2


Annular Eclipse 3


Sun without sunspots






Equipment used # 40mm spyglass # Point-and-shoot digital camera,

Sunday, 3 October 2021

MY THOUGHTS ON WORLD ENVIRONMENT DAY

 


Today 5th June 2021, the World celebrates World Environment day. I note it but, do not celebrate as in my mind, there is nothing to celebrate.

More than half-century ago Sri Lanka boasted considerable forest cover with plentiful wildlife, an almost pristine ocean replete with marine life including, my speciality, sharks. On clear nights the unpolluted atmosphere enabled one to see with the naked eye an array of stars, planets, the milky way and the occasional comet. Even under these idyllic conditions renowned environmentalists like Lyn De Alwis, Thilo Hoffmann, Sarath Kotagama and many others warned that, given the large number of environmental threats, conditions could soon take a turn for the worse. Although I was an experienced jungle man and diver since my school days, I really got involved in the environmental conservation movement when I joined the Wildlife and Nature Protection Society in 1970. While I was aware of the threats I assumed that, if uncontrolled, the problems would manifest themselves long after I had entered “That unknown country from whose bourne no traveller returns”. How wrong I was! The decline set in much faster than my colleagues or I ever expected.

Today, Sri Lanka is smitten with threats which no one could foresee a half-century ago. Our forests have been devastated, our wildlife endangered and iconic species, including our leopards and elephants, threatened with extinction within the next decade or so unless some miracle occurs. Our seas have been polluted, overfished and some species are on the verge of extinction. A new generation of Sri Lankan divers has, for example, never seen a Giant Grouper or Grey reef shark underwater. Today one must get away from the cities to a dark site to see the Milky Way, Omega Centauri or Andromeda Galaxy with the unaided eye.

What has happened? There are many reasons which have been dealt with by more competent people than I but, in my mind, the most important is the continuously expanding human population with its ever increasing demands on limited resources. As Bittu Sahagal, a great Indian environmentalist once said to me many years ago “We must understand that population and consumption are the same thing”.

Next to the matter of an exploding population is, to me at least, human greed which will lay waste to thousands of hectares of natural habitat to fill the coffers of a few privilaged individuals. This brings to mind a saying attributed to an old Native American chief who once said "Only when the last tree has been felled will we realise that we cannot eat money".

So what is the solution? Regrettably I have no answer to offer. The fact is, I am a part of the problem, I am not a part of the solution.

A glimmer of hope exists in that there is great environmental consciousness in the population today, especially among the younger generation who are performing yeoman service in making their peers, elders and others aware of the problems Sri Lanka faces. Education and information are important but is this enough? Only time will tell and unfortunately there may not be much time left before we have to face Armageddon.



 Rex I. De Silva’s Diving History




Rex Ian De Silva FLS MIBiol is compiler of this site. He is a pioneer Sri Lankan diver who has been diving and spearfishing since 1955. He was Secretary and Spearfishing Captain of the Reefcombers of Ceylon, one of the World’s earliest diving clubs. He became a commercial diver in 1968 and continued to dive professionally for over eighteen years. Although no longer diving professionally, he continues to dive for sport and research purposes. He is author of the definitive work '‘The Sharks of Sri Lanka' and approximately 120 scientific research papers, book chapters and other publications.. In 2013 Rex was declared an ‘International Legend of Diving’. Rex is an authority on Sri Lanka’s diving history as he was, and is, an integral part of it . His achievements are detailed below.

 

·        Started spearfishing around 1956 and SCUBA diving c. 1958.

 

Some activities as a commercial diver (from 1968 to 1985).

Posts held:

·         Chief Diver for ‘Mobile Marine Engineering Company’ (Colombo) 1968-1974.

·         Head of ‘Premier Engineers (Colombo) commercial diving unit’ 1974-1985.

 

Summary: 

·         Qualified for Colombo Port Commission Commercial Divers’ Licence in 1968.

·         Underwater hull cleaning of Supertanker M/t. “San Juan Vanguard” (165,000 tons) – the largest vessel to dock in Colombo Harbour at the time (1972).

·         Underwater hull cleaning of 44 cargo vessels in Colombo and Trincomalee harbours.

·         Stern tube sealing of several vessels in the Port of Colombo

·         In situ repair of the damaged underwater section of the hull of M/v “Pulawy” (20,000 tons) in 1974 preventing it from sinking in Colombo Harbour.

·         Salvaged cargo of mining equipment from the “Wombat” sunk in deep water off Nilveli Point.

·         Refloated trawler “Maple Leaf” sunk in Colombo Harbour.

·         Recovered main anchor of M/v. “Drachenfels” (30,000 tons) lost in silt in Colombo harbour.

·         Underwater sealing of the damaged scour gate and outlet at Hasalaka tank (reservoir) to prevent it from losing its water content during the cultivation season.

·         Underwater sealing of main outlet of Maduru Oya reservoir.

·         Underwater salvage operations at Maduru Oya reservoir

·         Annual underwater maintenance and clearing of the main intakes at Kelanitissa power plant (1970s).

·         Underwater salvage operations in Castlereagh Reservoir.

·         Underwater search for and recovery of drowned corpses.

·         Training of individuals for commercial diving operations.

·         Miscellaneous diving, search, rescue, and salvage operations.

·         Diving operations carried out in the Maldives on Japanese     HOKO company fishery factory vessels.

L         

Equipment used:

·         SCUBA single and twin sets

·         Surface air supply equipment (Hookah) and Air Buoy.

·         First to operate ‘Brush Buoy’ hydraulic underwater hull-cleaning machines in Sri Lankan harbours.

·         Oxy-arc underwater cutting equipment used in salvage work.

                                                                    

Sport Diving

·         Honorary Secretary and Spearfishing Captain of the “Reefcombers of Ceylon” diving club from the mid-1960s. 

·         Began underwater photography in   November 1967.

·         Spearfishing Captain of Kinross Swimming & Life Saving Club 1974.

·         Largest fish speared 115lb Ray.

 

Scientific activities

·         Studying sharks and marine life since c. 1968.  Documented 22 shark species which had previously not been recorded from Sri Lanka. Documented a further three species of sharks and a single Chimera (Ghost shark) with colleagues.

·         Author of 120 peer-reviewed scientific papers, book chapters, articles and other publications on Sri Lankan marine life.

·         Declared an "International Legend of Diving" by the Legends of Diving Organization (USA) in 2013.

·         Author of THE SHARKS OF SRI LANKA. 2015.

·         Currently writing a “History of Diving in Sri Lanka”









Comments

·         “I have known Rex I De Silva for over two decades and admire his work and accomplishments in underwater exploration, wildlife and astronomy”.     Sir Arthur C. Clarke, Chancellor University of Moratuwa. 29 September 2001.

 

·         “Mr. Rex De Silva, ‘Renaissance Man’, Naturalist, Environmentalist, Deep Sea Diver, Birder, Martial Arts expert and Scholar is as unusual as they come”.   Vidya Jyoti Ashley de Vos, President of the Wildlife and Nature  Protection   Society of Sri Lanka (1999-2000). 8th October 2001

 

·        “[Rex De Silva] is a person with an excellent knowledge of the ocean, land and sky”.                                                                                  Professor Sarath Kotagama, University of Colombo.


Other:

·         In early 1970s held the Reefcombers SCUBA depth record at 240 feet in the Trincomalee Submarine Canyon. This was also the unofficial Sri Lankan SCUBA depth record. 

Logged an estimated 8,000 - 10,000 dives between 1956 and 2010     

·  Read “Dharshana Jayawardena interviews Rex I De Silva” at: https://reximages.blogspot.com/2017/04/dharshanajayawardena-author-of-ghosts.html

·   Listed in ‘Who’s who of Sri Lanka’ (volume II).

 

Other Interests and activities:

 

·         Former astronomical (lunar occultations) observer for the United States Naval Observatory (USNO) Station reference SXT94.

·         Current observer/photographer of solar activity.

·         Holder of advanced Black-belt degree in Shotokan Karate and holder of Master Instructor’s certification (SHIHAN) in martial arts. 


Awards

 

 Abacus Institute: Honorary Diploma for “Outstanding contributions in the field of Environmental Protection", Marine Conservation Forum Award and Mid-city Rotary Vocational Services Award etc.


 




Text corrected and updated on 10th February 2023



                                                                                                                          © Rex I. De Silva

Sunday, 26 September 2021

 

              

WATCHING SEABIRDS WITH VINTAGE OPTICS – A DIY APPROACH

In the decades gone by I used several telescopes to study seabirds. These included, among other things, two good 80mm spotting scopes (on loan from a conservation organisation) and a small 40 mm vintage (53-year-old) terrestrial refractor or ‘Spyglass’. The two spotting scopes were returned in due course so I have now fallen back on my old spyglass. Some birders seeing this prehistoric looking instrument often look at me with barely disguised contempt: that is until they look through it. The vintage instrument gives sharp high-resolution images of high contrast with an, admittedly, rather small field of view. So what is the secret? Very simple, as it is not ‘nitrogen filled’ I can easily dismantle the scope into its individual components without the use of tools, for cleaning, servicing etc. An exception being the objective and ocular retaining rings which require a small screwdriver, toothpick or ballpoint pen tip for removal. When something is easy to maintain, the chances are high that it will be properly maintained which, in this case, is mainly cleaning of the lenses internally with proper lens cleaning equipment and methods.

I have modified the scope somewhat. To improve image contrast, I lined the interior surface of the optical tube with black velvet and blackened the objective edge with indelible ink. Furthermore, I always carefully tighten the objective retaining ring so that it holds the lens securely but never too tight, as overtightening sets up stresses in the glass which, to some extent, can adversely affect the image. Of course gross overtightening can crack the lens rendering the instrument useless.

 

Accessories can sometimes assist observations. For example, the use of filters can improve visibility during misty or foggy conditions. To cite an example: in Colombo mist occurs offshore on November mornings making observation difficult. A suitable filter can help here. As my scope is not threaded for filters I constructed an adapter out of a short piece of plastic water pipe to enable the use of HOYA glass photographic filters in front of the objective cell. The use of a minus-violet (Y44) or a yellow (K2) filter have permitted me to glimpse birds which would otherwise have been lost in the fog. I also occasionally use a linear polarizing filter (PL) to reduce reflections off the sea surface and a UV filter for permanent lens protection.

 

Lastly, the scope is best mounted on a steady tripod. The professional video tripods are ideal, but these are usually too heavy and also very expensive. I therefore modified a normal camera tripod with tubular legs by loading the bottom section of each leg with weights. Lead shot is ideal but I used nails (with a little engine oil to prevent rusting). A cork plug in each leg ensures that the weights do not move. I have fitted a snap swivel to the bottom of the tripod's centre column; weights can be hung from this when extra stability is required. 




©Rex I. De Silva   

Tuesday, 23 March 2021





UFOs and Aliens

                                                                                                      


"People often don't want facts getting in the way of a   good  story"


I am often asked if I believe in UFOs, and on being informed that I do not, my interlocutor's response is frequently something like this; “So does that mean you do not believe in intelligent life in the Universe?”. This is not the case and the comments below will explain and clarify my views.


Aliens
The term "Alien" is often used to describe the hypothetical “Little Green Men” from outer space who allegedly pilot flying saucers and UFOs and interact with humans – sometimes abducting them. In this context I do not believe in "Aliens". On the other hand when the expression "Aliens" refers to extra-terrestrial intelligent beings; then my answer is a qualified “They must almost certainly exist somewhere in a vast Universe like ours, although at present we do not have any compelling evidence to support their existence".


UFOs (Flying Saucers)
To some the belief in UFOs is an act of faith like a belief in astrology, the Mars face, Atlantis, paranormal activity and the Bermuda Triangle; hence it is something that most astronomers would prefer to ignore. My view is that far from being piloted by aliens and coming from the depths of space most “sightings” of UFOs have much more prosaic explanations. These include misidentification of known astronomical, meteorological or geophysical phenomena. Some alleged sightings may also refer to man-made objects such as aircraft, reentering rocket boosters, UAVs (drones) etc. Those alleged sightings of UFOs which cannot be explained by any of the foregoing are, in my opinion, psychological phenomena which take place in the human mind and are therefore best investigated by the psychologist or psychiatrist. For example many reports of alien abductions can be explained by hypnagogic and hypnopompic hallucinations, whereas a high level of dopamine in the brain can also trigger hallucinations of aliens and abductions. Another phenomen Pareidolia (seeing familar objects in random patterns) could be a contributory factor. A further discussion of this interesting subject is beyond the scope of this account. Additionally one must always keep in mind the possible activities of hoaxers. Especially suspicious is information gathered under hypnosis. It is well known and scientifically established that "Hypnosis stimulates the imagination and not the memory". (This is the reason that most courts do not permit evidence gained under hypnosis). And what about those compelling images of UFOs? I believe that most actually demonstrate the amazing versatility of modern digital photography and image-processing software.


Have I seen UFOs? Yes: in over half-century as a recreational astronomer, I have seen more than my share of mysterious objects in the sky. However after reflection, careful consideration, research, the application of scientific logic, critical thinking and most of all the use of plain commonsense, virtually all of these have turned out to have relatively mundane (i.e. non UFO) explanations.


Intelligent life in the Universe
To say there is no life in the rest of the Universe would be to take us back to the dark ages of pre-Copernican thinking when it was believed that the Universe was Earth-centered and the planets, stars etc. were all in orbit around us and man was the master of it all. There is little doubt in my mind that life, and intelligent technological life, exists elsewhere in the Universe. Nevertheless, in our present state of ignorance, this can only be speculation. There is a suggestion that life may have originated more than once on earth. If this is proved correct it gives hope that life may be fairly common in the Universe as well.


Given the enormous distances between stars, any communication between two neighbouring star systems would take a very long time. For example using radio to say “Hello” to an intelligent creature in the Alpha Centauri system (the star system closest to Earth at 4.3 light years) and receive a "quick" reply would take 8.6 years; and most stars are tens, hundreds, thousands or millions of light years away. A visitor from another star system travelling in his spaceship at almost the speed of light will, if his star system is one thousand light years away, take around 1,000 years to reach Earth, where I'm certain he would find more useful things to do than go around building pyramids or stone circles, interbreeding with humans, frightening people or abducting them.


One point that is often overlooked in discussions such as this, is that for one civilization to visit another the two must be contemporaneous and their technological civilizations must be fairly long lived. What are the possibilities of this in comparison to the enormous age of the Universe? An interesting possibility would be that of two technological civilizations in star systems relatively close to each other, but separated in terms of time so that neither would have any knowledge of the other. A hypothetical example is that of an intelligent race which became extinct, say, one million years ago in the Alpha Centauri system. Their last dying radio broadcasts and possibly calls for help would have reached Earth when our caveman ancestors were chipping stone tools and rubbing sticks together to make fire; so we modern humans would be totally ignorant of their existence.


The point I am making is that while it is likely that other technological civilizations exist in the Universe, the chances that hypothetical "Aliens" are visiting, or even communicating with us is vanishingly small. Of course if all the speculation about wormholes, branes, faster-than-light travel and parallel universes is correct then . . . . .


Hopefully the SETI project, and others like it, will soon find evidence to answer these questions. I eagerly await the first acceptable evidence for extraterrestrial life, especially intelligent life. I must say however that I have seen no unequivocal evidence for Aliens visiting, or having ever visited, the Earth. The so-called "evidence" often put forward for Alien-inspired Nazca lines, Pyramids, Crop circles etc. is, in my opinion, nothing more than uninformed speculation. The Nazca lines, Pyramids and Crop circles can easily be explained by more prosaic human activity.  So until scientifically acceptable evidence is forthcoming, I expect to devote my time to "Real" astronomy and will leave further speculation on the subject to others.


So hopefully, you will not hear anything more on this subject from me.

This is my personal opinion and if you disagree with my views that is your prerogative which I respect.
                                                                 


                                                 © Copyright Rex I. De Silva. All rights reserved.