Safety

Popular, and tricky. The Top 6 Dive Sites That Demand Extra Caution

Exploring some of your favorite dive destinations. Here’s what you need to know to dive them safely and confidently

Divers, as we all know, are travellers. The DAN Europe alarm centre regularly receives requests for assistance from members from all over the world. Interestingly, the distribution of calls on the world map shows which are the favoured destinations by European DAN members. It also shows that a substantial number of calls for assistance comes from a selected cluster of specific dive sites. We decided to take a closer look at these sites, and selected the first six on the list. The aim is not to discourage divers from visiting those sites. On the contrary: we want them to continue to travel and dive there too, but with a few extra tips to improve safety. An increasingly informed community is a safer community.

Are some dive sites/destinations more riskier than others?

That a coral garden at -12m in clear, protected waters presents less of a challenge to a diver than a deep wreck lashed by currents is quite intuitive. Some dives require more experience, specific training and equipment which must be appropriate to the conditions one intends to face. Nonetheless, DAN receives requests for assistance more frequently from some popular, most dreamed of and famous diving destinations. It’s the law of the big numbers. World class dive sites such as the Thistlegorm and the Zenobia wrecks, or Dahab’s Blue Hole are frequently the aim of diving pilgrimages. It’s not surprising then that we have statistically recorded more incidents at these locations compared to other destinations with a similar environment.

We analysed the most important aspects of these sites, using valuable input and assistance from dive professionals who are familiar with the sites, and part of the local diving community.

The list only takes into account the calls managed by the DAN Europe alarm centre, and does not include requests for action submitted to other organisations such as Harbour Offices, Police, SAR, the various NHSs etc.

THE TOP 6

#1 Blue Hole

Dahab, Sinai Peninsula, Egypt – Shore diving.

The Blue Hole in Dahab is a true Mecca for technical divers and freedivers from all over the world. It is a very deep (over -120m) karst sinkhole formed by erosion within the fringing reef. At -55m an archway connects the Blue Hole’s inner waters with the open sea. According to several sources, the Blue Hole is the dive site where most fatal diving accidents occur in the world.

Critical issues

• Good visibility and good sea conditions can be deceptive about depth and dive’s difficulty
• Disorientation
• A diver unfamiliar with the site may wander too long at depth, or even get lost, while searching for the arch (exit tunnel)
• Unskilled divers venturing beyond the limits of their training level
• Narcosis
• Freedivers plunging without a safety team, or without a buddy
• Bets between divers
• Dehydration

How to survive the dive.

Community notes by the author, who has 12 years of experience as dive guide and instructor in the Red Sea, Chamber Attendant at HyperMed in Sharm El Sheik

For recreational divers:

Much preferable is the tour of the outer wall, entering and exiting the Blue Hole through a shallow saddle (at -6 metres) or even starting the Dive from The Bells. The inner walls of the Blue Hole are barren, completely devoid of attractions at recreational depths. Hydrate yourself. Attempting to cross the arch with a 12-litre exposes yourself to: severe narcosis, disorientation, running out of air.

For freedivers:

Do not dive alone [Ed. note: This is a cardinal rule of freediving; always have a buddy ready to effect a rescue). Always rely on some of the many local freediving centres.

For all others:

Rely on local technical diving centres or guides of confirmed professional rigour. Check your equipment. Get hydrated.

#2 SS Thistlegorm

Shaab Ali, Gubal Strait, Gulf of Suez, Egypt – Wreck Dive

The wreck of the Thistlegorm is considered by many a time machine lying on a 32-metre seabed. As a British cargo ship, she was crammed with military supplies and ammunition when she sank in October 1941 after a bomb dropped by a German bomber. The wreck contains jeeps, trucks, small tracked vehicles, motorbikes, and weapons. A local saying claims that the Thistlegorm collects in more revenue than the Pyramids of Giza. However, this dive site accounts for the highest number of diving incidents in the Sharm El Sheikh area.

Critical issues

• Strong currents, rough seas and poor visibility are the norm
• Square profiles
• Performing the safety/decompression stop at the same depth on the same ascent line can be a treacherous task for a large group of divers.
• Boats manoeuvring at the surface
• Ladders and platforms are extremely mobile in rough seas
• Lack of rest (the trip to the wreck can start very early in the morning)
• Dehydration and nitrogen accumulation can contribute to the onset of DCS

Photo credit: Stefano Gualtieri

Surviving the dive

Community notes by the author

Memorise carefully the guide’s briefing. If you descend or ascend along a mooring line and current is present, NEVER think to lose your grip. If you lose your group, ascend along the mooring line. If you can’t recognise your boat’s mooring line, don’t waste time and climb up from any. Floating platforms on the surface and propellers are your worst enemy: when ascending as well as descending ALWAYS LOOK UP towards the surface. While entering the water, move away from the platform immediately. During the descent, and especially on the ascent, along the line check your buoyancy constantly. Follow the guide or the group, do not linger. Forget compressed air: use Nitrox. Avoid clubbing at least the night before. Don’t wait until you are thirsty to drink, hydrate yourself beginning the day before.

#3 MS Zenobia

Larnaca, Cyprus, Eastern Mediterranean – Wreck-Dive

This Swedish-built ferry sank near the port of Larnaca in 1980 due to an error in the on-board software that pumped ballast water to the wrong side. About 170 metres long, she lies banked on her port side between 17 and 42 metres depth with her well known cargo of cars still on board. As this dive is quite easy to perform, it is suitable for an external tour by open water divers. Currently, it is one of the most visited wrecks in the world.

Critical issues

• Sharp metal
• Square profile
• Disorientation due to severe wreck dislocation
• Unskilled divers venturing beyond the limits of their training
• Marine life stings
• Failures on checking the no decompression limit (NDL)
• Dehydration

Surviving the dive

Community notes by Chris Demetriou, Dive centre Manager, DAN Instructor Trainer, Chamber Attendant, Chamber Operator, Cyprus

Before diving it is good to get informed, be fit and have insurance. Reliable centres can be found through the Cyprus Diving Centre Association (CDCA), DAN HIRA centres or ISO EN 24803-compliant centres. Listen and follow the dive briefings, you will see more and the guides know the best spots. Use mooring lines for controlled descents and ascents, wear a computer, use nitrox and monitor your NDL. Penetration dives vary in difficulty: be aware of your limits, your gas requirements and have the correct equipment for each dive. The wreck has sharp edges and marine life can sting, so good buoyancy control is essential to avoid both types of danger. Also, keep in mind that temperatures in Cyprus can get very hot, so stay hydrated.

#4 Haven

Arenzano, Liguria, Italy – Wreck Dive

Amoco’s 344-metre-long supertanker caught fire in April 1991 in Genoa harbour. It contained 144,000 tonnes of crude oil and 12,000 tonnes of fuel. After breaking its moorings, it drifted and burned, then sank one mile off the coast of Arenzano on a 90-metre seabed. The oil spilled from the Haven caused the worst environmental disaster in the Mediterranean Sea. It is the largest visitable wreck in the Mediterranean. Following some serious accidents involving recreational divers, diving activity is now strictly regulated and monitored.

Critical issues

• Depth
• Possible disorientation in the blue, even while holding a line.
• Square profile
• Divers’ failing to perform their equipment checks
• Dive planning errors
• Currents
• Long distances between points of interest

Photo credit: Niccolò Crespi

Surviving the dive

Community notes by: Niccolò Crespi, Tech Instructor, Commercial Diver, Italy

The wreck doesn’t have any specific critical issues, the visibility is often excellent, fishing nets or other entanglements are not present, and the engine room itself is very large. Technical divers typically rely on a line for penetration attempts and typically stay hydrated. The biggest issue about the Haven, in my opinion, is in the heads of some divers. Despite local operators insistently repeat to perform pre-dive rebreather checks and remember to open their oxygen valves, there have been a number of cases of hypoxia in the very first minutes of the dive. Always use the mooring lines for ascents and descents. For those wishing to take an external tour of the wreck, the use of a scooter/DPV is recommended.

#5 Garda Lake

Lombardia/Veneto/Trentino-Alto Adige, Italy

The largest of the Italian lakes, whose shores bath three Italian regions, is a well-known destination for divers from northern Europe, who can find more exciting depths and a nicer climate in Garda than in the Baltic Sea or the winterly frozen alpine lakes. In addition to the typical freshwater life, Garda Lake is home to wrecks dating back to WWII. Diving conditions may vary in the presence of winds.

Critical issues

• Depth
• Square profiles
• Divers venturing beyond the limits of their training
• Failure on assessing one’s own limits
• Bad dive planning
• Dehydration
• Bets between divers

Photo credit: Giuseppe Pastoressa

Surviving the dive

Community notes by Davide De Lorenzi, Dive Centre Manager, DAN Instructor, Italy

Lake Garda hosts almost vertical walls plunging even beyond -200 metres. Many of the available dive sites are accessible from the shore, so divers don’t feel the need for the support of a diving centre or boat. A trained, organised and competent diver will find everything he or she wants. The factors that predispose to diving accidents are often the following: dehydration, cold, fatigue, breathing gas density, and dive planning. The first piece of advice is to use common sense. Understand whether to dive or abort the dive. Listen to your inner voice before engaging in the dive.

#6 El Hierro

Canary Islands, Spain.

Among the Canary Islands, El Hierro is one of the wildest. Local fishing around the island is artisanal only, and the volcanic walls are home to marine life treasures and deep canyons. Out of the whole list, it is the only destination with a peculiar critical side: getting to altitude after diving. This is also the main cause of requests for assistance to DAN Europe from El Hierro. It seems that many divers choose to stay in resorts or holiday homes sited at altitude. Notably the main town, Valverde, is situated at 571m above the sea level.

Photo credit: Pietro Cremone

Surviving the dive

After diving, it is never a good idea to go to altitude – let alone flying – for the next 24-48 hours, depending on the repetitiveness and depth of performed dives. For sea level diving, the limit set by DAN and the most respected research institutes is 300 metres above sea level.

Conclusions

For the most part, there are no inherently dangerous dives, only dives that require more attention, training, proper planning, fitness, and awareness about one’s own limits. This applies to all dives with similar characteristics to those listed above. If other dive sites are not in the Top 6 list, there is one simple reason: fewer divers go there.

One last thing we’ll never stop repeating: dehydration is one of the main contributing factors to decompression illness (DCI). It is especially true where temperatures are high, and the air is dry. Dehydration can be as well a consequence of alcohol drinking, consumption of theine and caffeine (contained in many colas and energy drinks) and sweetened soft drinks. It is always good to start hydrating a few days before the beginning of the diving week by drinking water and taking hydrating salts.

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Acknowledgements: Chris Demetriou, Davide De Lorenzi, Niccolo Crespi.

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About the author

DAN Member since 1997, Claudio Di Manao is a PADI and IANTD diving instructor. He’s the author of a series of books and novels about diving, including Shamandura Generation, an exhilarating portrait of Sharm el Sheikh’s diving community. He collaborates with magazines, radios and newspapers, talking and writing about diving safety, marine life and travels.