<br />
The Official Magazine of Britain's Biggest Diving Club<br />
THE SCIENCE ISSUE · Get smart with marine surveys<br />
· Nudi Nirvana in the Scillies<br />
· Real world gas physics explained<br />
· Coral rebirth in Bonaire<br />
ALADIN<br />
SPORTS<br />
MATRIX<br />
TRIED AND TESTED<br />
North Shoal: Andy Hunt reports on the discovery of a virgin wreck<br />
HMS Vanguard: Marking the centenary of the Scapa maritime disaster<br />
SS Excellent: The shallow wreck in Gibraltar that lives up to its name<br />
Issue 68 July 2017 £3.99<br />
<br />
Welcome<br />
Hello and welcome to this science-themed issue of SCUBA. You could say that everything we do in diving is<br />
underpinned with science, going right back to the experiments of John Scott Haldane, the physiologist with<br />
a penchant for acting as his own gui<a title="iSCUBA 68 - July 2017 page 1" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=1"> The Official Magazine of Britain's Biggest Diving</a>
<a title="iSCUBA 68 - July 2017 page 2" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=2"> </a>
<a title="iSCUBA 68 - July 2017 page 3" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=3"> Welcome Hello and welcome to this science-themed </a>
<a title="iSCUBA 68 - July 2017 page 4" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=4"> Published by: TRMG Ltd Winchester Court, 1 Forum</a>
<a title="iSCUBA 68 - July 2017 page 5" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=5"> Issue 68 July 2017 CONTENTS 62 </a>
<a title="iSCUBA 68 - July 2017 page 6" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=6"> BSACCONTACTS Be part of it - WANT TO LEARN T</a>
<a title="iSCUBA 68 - July 2017 page 7" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=7"> </a>
<a title="iSCUBA 68 - July 2017 page 8" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=8"> SCUBAHUB A brief moment of stillness Californi</a>
<a title="iSCUBA 68 - July 2017 page 9" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=9"> 9</a>
<a title="iSCUBA 68 - July 2017 page 10" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=10"> SCUBAHUB Critter confidential Great spider cra</a>
<a title="iSCUBA 68 - July 2017 page 11" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=11"> SCUBAHUB QLeft: A sea toad investigates the front</a>
<a title="iSCUBA 68 - July 2017 page 12" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=12"> SCUBAHub Come and have a go if you think you're t</a>
<a title="iSCUBA 68 - July 2017 page 13" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=13"> SCUBAHUB Dredge-damaged sea loch now protected </a>
<a title="iSCUBA 68 - July 2017 page 14" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=14"> SCUBAHUB BSAC AGM 2017: New faces and THE club'</a>
<a title="iSCUBA 68 - July 2017 page 15" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=15"> SCUBAHUB plans for the future Deric is honoured</a>
<a title="iSCUBA 68 - July 2017 page 16" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=16"> </a>
<a title="iSCUBA 68 - July 2017 page 17" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=17"> SCUBAHUB Cover up this summer BSAC i</a>
<a title="iSCUBA 68 - July 2017 page 18" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=18"> SCUBAHUB Pathfinder relative thanks BSAC tech te</a>
<a title="iSCUBA 68 - July 2017 page 19" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=19"> SCUBAHUB Exclusive discounts on APD kit BSAC has </a>
<a title="iSCUBA 68 - July 2017 page 20" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=20"> SCUBABLOKE Going to extremes How far would you go</a>
<a title="iSCUBA 68 - July 2017 page 21" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=21"> </a>
<a title="iSCUBA 68 - July 2017 page 22" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=22"> </a>
<a title="iSCUBA 68 - July 2017 page 23" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=23"> SCUBAWOMAN Gotta lotta bottle As part of this iss</a>
<a title="iSCUBA 68 - July 2017 page 24" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=24"> SBelow: Andy gazes down at the sunlit garden bene</a>
<a title="iSCUBA 68 - July 2017 page 25" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=25"> SCUBAHUB RAbove: Taking a close</a>
<a title="iSCUBA 68 - July 2017 page 26" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=26"> Please keep subm tted letters to no more than 200</a>
<a title="iSCUBA 68 - July 2017 page 27" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=27"> SCUBACHAT Back in time with Torbet Andy Torbet's </a>
<a title="iSCUBA 68 - July 2017 page 28" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=28"> </a>
<a title="iSCUBA 68 - July 2017 page 29" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=29"> SCUBACHAT Remembering the Vanguard The value </a>
<a title="iSCUBA 68 - July 2017 page 30" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=30"> COURSE DIARY Develop your diving with BSAC Our Co</a>
<a title="iSCUBA 68 - July 2017 page 31" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=31"> BSACCOURSES SKILL DEVELOPMENT COURSES (SDCs) JUL</a>
<a title="iSCUBA 68 - July 2017 page 32" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=32"> CLUBFOCUS Kiwi Divers As a military BSAC branch, </a>
<a title="iSCUBA 68 - July 2017 page 33" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=33"> downs by New Zealand soldiers at the end of the F</a>
<a title="iSCUBA 68 - July 2017 page 34" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=34"> CLUBFOCUS anything from a couple of weeks to 12 </a>
<a title="iSCUBA 68 - July 2017 page 35" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=35"> CLUBFOCUS SOCIAL MEDIA HELPS RECRUIT Social medi</a>
<a title="iSCUBA 68 - July 2017 page 36" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=36"> EXPEDITIONDIVING Sun, sea and citizen science Al</a>
<a title="iSCUBA 68 - July 2017 page 37" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=37"> EXPEDITIONDIVING Divers everywhere are becomin</a>
<a title="iSCUBA 68 - July 2017 page 38" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=38"> EXPEDITIONDIVING RAbove: Good buoyancy control i</a>
<a title="iSCUBA 68 - July 2017 page 39" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=39"> </a>
<a title="iSCUBA 68 - July 2017 page 40" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=40"> </a>
<a title="iSCUBA 68 - July 2017 page 41" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=41"> EXPEDITIONDIVING Day two Our next day focused on</a>
<a title="iSCUBA 68 - July 2017 page 42" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=42"> EXPEDITIONDIVING PHOTO: JUDITH RIETVELD area o</a>
<a title="iSCUBA 68 - July 2017 page 43" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=43"> </a>
<a title="iSCUBA 68 - July 2017 page 44" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=44"> IN THE MIX Getting real with your gas Gavin Anth</a>
<a title="iSCUBA 68 - July 2017 page 45" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=45"> For most divers using air in cylinders with worki</a>
<a title="iSCUBA 68 - July 2017 page 46" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=46"> IN THE MIX combinati</a>
<a title="iSCUBA 68 - July 2017 page 47" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=47"> </a>
<a title="iSCUBA 68 - July 2017 page 48" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=48"> LEARNING CURVE FIRST CLASS DIVER PREP: Ia</a>
<a title="iSCUBA 68 - July 2017 page 49" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=49"> UBelow: Survey photograph showing bipod mast, eng</a>
<a title="iSCUBA 68 - July 2017 page 50" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=50"> LEARNING CURVE RAbove: Gordon sketches the s</a>
<a title="iSCUBA 68 - July 2017 page 51" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=51"> SBelow: A plan view from the stern, showing towin</a>
<a title="iSCUBA 68 - July 2017 page 52" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=52"> LEARNING CURVE surface exactly which bits of th</a>
<a title="iSCUBA 68 - July 2017 page 53" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=53"> </a>
<a title="iSCUBA 68 - July 2017 page 54" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=54"> TAKING CONTROL When the practice pays off Dive Le</a>
<a title="iSCUBA 68 - July 2017 page 55" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=55"> I responded instinctively – getting my husban</a>
<a title="iSCUBA 68 - July 2017 page 56" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=56"> An Orkney mystery LOCATION: West Orkney DEPTH: 30</a>
<a title="iSCUBA 68 - July 2017 page 57" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=57"> WRECKED! </a>
<a title="iSCUBA 68 - July 2017 page 58" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=58"> WRECKED! </a>
<a title="iSCUBA 68 - July 2017 page 59" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=59"> </a>
<a title="iSCUBA 68 - July 2017 page 60" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=60"> </a>
<a title="iSCUBA 68 - July 2017 page 61" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=61"> WRECKED! g lifeboat was the first to leave for </a>
<a title="iSCUBA 68 - July 2017 page 62" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=62"> UKDIVING Destination Scilly the science of squidg</a>
<a title="iSCUBA 68 - July 2017 page 63" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=63"> Q Left: Kate</a>
<a title="iSCUBA 68 - July 2017 page 64" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=64"> UKDIVING </a>
<a title="iSCUBA 68 - July 2017 page 65" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=65"> Five top dives 1 Flat Ledge, St Martin's Our fir</a>
<a title="iSCUBA 68 - July 2017 page 66" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=66"> UKDIVING 2 Wingletang Ledges North</a>
<a title="iSCUBA 68 - July 2017 page 67" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=67"> </a>
<a title="iSCUBA 68 - July 2017 page 68" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=68"> </a>
<a title="iSCUBA 68 - July 2017 page 69" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=69"> UKDIVING 3 The Gilstone After a dive on the Gilst</a>
<a title="iSCUBA 68 - July 2017 page 70" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=70"> UKDIVING 4 Cita I was absolutely </a>
<a title="iSCUBA 68 - July 2017 page 71" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=71"> </a>
<a title="iSCUBA 68 - July 2017 page 72" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=72"> UKDIVING 5 Diving with seals Even scientists can</a>
<a title="iSCUBA 68 - July 2017 page 73" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=73"> Q Left: Fun with the grey seals Halichoerus Th</a>
<a title="iSCUBA 68 - July 2017 page 74" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=74"> CENTENARYEXPEDITION HMS Vanguard lost but not for</a>
<a title="iSCUBA 68 - July 2017 page 75" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=75"> I remember going to the cemetery at El Alam</a>
<a title="iSCUBA 68 - July 2017 page 76" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=76"> RAbove: A 12-inch shell below the stern gun tec</a>
<a title="iSCUBA 68 - July 2017 page 77" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=77"> </a>
<a title="iSCUBA 68 - July 2017 page 78" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=78"> RAbove: Clarkson cases propped up against a bulkh</a>
<a title="iSCUBA 68 - July 2017 page 79" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=79"> CENTENARYEXPEDITION HMS Vanguard 100 </a>
<a title="iSCUBA 68 - July 2017 page 80" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=80"> TESTCENTRE Advanced nitrox thinking Scubapro's Al</a>
<a title="iSCUBA 68 - July 2017 page 81" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=81"> What a view! There are still divers out there who</a>
<a title="iSCUBA 68 - July 2017 page 82" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=82"> TESTCENTRE Fins for fun Ahigh performance pair </a>
<a title="iSCUBA 68 - July 2017 page 83" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=83"> </a>
<a title="iSCUBA 68 - July 2017 page 84" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=84"> </a>
<a title="iSCUBA 68 - July 2017 page 85" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=85"> TRAVEL FOCUS Departure lounge Travel news and of</a>
<a title="iSCUBA 68 - July 2017 page 86" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=86"> TRAVEL FOCUS FABULOUS FAKARAVA blue o two is o</a>
<a title="iSCUBA 68 - July 2017 page 87" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=87"> </a>
<a title="iSCUBA 68 - July 2017 page 88" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=88"> TRAVELSPECIAL Coral revival in Bonaire Carol Ma</a>
<a title="iSCUBA 68 - July 2017 page 89" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=89"> SBelow: Old stand of elkhorn coral among sea rods</a>
<a title="iSCUBA 68 - July 2017 page 90" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=90"> PHOTO: ALEJANDRO GUTIERREZ CUBA DOMINICAN HAITI </a>
<a title="iSCUBA 68 - July 2017 page 91" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=91"> TRAVELSPECIAL Coral recovery Francesca Virdis, d</a>
<a title="iSCUBA 68 - July 2017 page 92" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=92"> TRAVELSPECIAL </a>
<a title="iSCUBA 68 - July 2017 page 93" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=93"> </a>
<a title="iSCUBA 68 - July 2017 page 94" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=94"> SBelow: A giant fire worm hunting on pl</a>
<a title="iSCUBA 68 - July 2017 page 95" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=95"> First, we drove to the northern, more remote side</a>
<a title="iSCUBA 68 - July 2017 page 96" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=96"> PHOTO: ALEJANDRO GUTIERREZ </a>
<a title="iSCUBA 68 - July 2017 page 97" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=97"> TRAVELSPECIAL PRight: Natural </a>
<a title="iSCUBA 68 - July 2017 page 98" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=98"> PHOTOQUEST Shellfish inclinations This month Tr</a>
<a title="iSCUBA 68 - July 2017 page 99" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=99"> PHOTOQUEST In my image of this long-clawed squa</a>
<a title="iSCUBA 68 - July 2017 page 100" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=100"> YOUR POSTCARDS Every month we will publish a seri</a>
<a title="iSCUBA 68 - July 2017 page 101" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=101"> POSTCARDS This girl ca</a>
<a title="iSCUBA 68 - July 2017 page 102" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=102"> </a>
<a title="iSCUBA 68 - July 2017 page 103" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=103"> </a>
<a title="iSCUBA 68 - July 2017 page 104" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=104"> </a>
<a title="iSCUBA 68 - July 2017 page 105" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=105"> Contributors Gavin Anthony wrote this month's I</a>
<a title="iSCUBA 68 - July 2017 page 106" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=106"> MY GREATEST DIVE By name and nature Sometimes t</a>
<a title="iSCUBA 68 - July 2017 page 107" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=107"> </a>
<a title="iSCUBA 68 - July 2017 page 108" href="https://secure.viewer.zmags.com/publication/4b5ce3a9?page=108"> </a>