Tiger sharks have a fearsome reputation, yet safe interaction with divers can go on for hours.

A BLACKTIP SHARK JUMPED CLEAR of the water in an amazing display of excitement that heralded our first sight of a tiger shark, doing figures of eight below our RIB. She was moving purposefully in the smell corridor on which we had been briefed only minutes before.
It was time to test our mettle. We decided to get in before we could catch sight of the other sharks being greeted by Sean and Mark, our guides and guardians.
Was it a sane decision to trust them that we would be safe in the proximity of such daunting animals They did seem to know every animal personally, naming each one as it cleared a path through the cloud of blacktips. Having travelled this far for the experience, I wasnt going to chicken out now.
Once in the water my buddy Kirsty and I quickly dropped to 6m. All-round visibility felt much safer than being on the surface, wondering what was approaching our feet. The circus with which we were presented was awe-inspiring. Adrenalin-charged, it took some time to control heartbeat and full consciousness as the large blacktips swirled, dodged and weaved in and out of each other, occasionally clearing to reveal a sleekly serene tiger shark slowly and deliberately investigating the bait.
Watching these animals at home in their environment is something I will never forget.
Mark and Gail Addison of Blue Wilderness have been studying the resident tiger sharks of Aliwal Shoal for many years, and the main purpose of this three-day trip was to fix Pop-up Archival Tags (PATS) to two females prior to their winter roaming.
It is thought that the tiger sharks may travel up the east coast of South Africa to Mozambique. Research has been carried out on their deepwater travels in Hawaii and their shallow-water movements in California, but none had been done to date to track their movements in South Africa.
Tourists help pay for the research and study of the tiger sharks, although the tagging operation is being sponsored by Save Our Seas. The study is planned to continue and expand through 2007.
Each tiger-shark dive lasts for up to two hours in the water, with an option to snorkel if youre really brave.
Staying at an average depth of 6-8m, the length of dive depends purely on your air consumption and the weather. We were there in May, when a 5mm wetsuit should keep you cosy for the duration. Mark will not drag you out of your adventure early so long as he can continue to monitor all the divers safely.
Once a tiger shark has been attracted by chumming, divers enter the water and the bait drum is released from its anchorage. The anchorage is chosen based on local conditions each day,
a strong current being ideal. Divers and drum drift together across the shoal in a surprisingly relaxing and truly absorbing dive.
The sheer number of sharks and encounters we saw each day was astounding. At first there were too many to count, but at various points there were in excess of 50 blacktips, and they are frenetic, fast and inquisitive.
Most were more than 1.5m long and all were female. They would circle and surround the bait drum for the duration, clearing a path only for the much larger tiger sharks.
Some animals were very inquisitive. One in particular seemed to love the electrical output of recycling strobes, because I saw her distinctive markings close up on all three dives.
We experienced visitations by nine separate tiger sharks on one dive as we drifted through their territories over the shoal, or as they were enticed in by the smell corridors produced by the chum slick. Mark warned us about keeping out of these corridors, as the presence of a diver would often deter a tiger from approaching the bait drum.
This difficult task was aided by the presence of Sean on the surface, who acted as our reference point. Snorkelling and free-diving, he would watch over us and ensure that we kept in the right position relative to the bait and currents.
He would also identify individual animals and watch for any threatening or aggressive behaviour. Marshalling us and ever-present, his confidence and capabilities were very reassuring, especially at the start of the first day!
Ranging from 2m to 4m-plus in length, the tigers were all female. Males are apparently a rarity here.
The larger animals inhabit the outer territories of the shoal, the juveniles staying inshore. Mark was observing definite pecking orders and dominant social groups in his research, and very large females were rarely seen together.
Once attracted, the tigers could be witnessed circling under the bait on the bottom before moving vertically up towards the bait drum, providing a stunning spectacle but one you wouldnt want to be too close to.
The youngsters in particular sometimes came close to investigate divers; they are attracted by yellow fins and, as Kirsty found, octopus hoses!
If you want a lot of very close encounters with these animals, find a fluorescent yellow wetsuit. Moving very gracefully and surprisingly slowly (especially in relation to the blacktips), these animals are very easy to push away gently with a hand on the nose.
Aliwal Shoal is south of Durban and diving is based out of Umkomaas, where a number of good dive operators are based. The shoal is sometimes visible and depths vary down to 32m. Full of tropical and sub-tropical life, this is now a protected area.
In addition to the usual (and unusual) reef species that can be observed, we saw a minke whale and a pod of dolphins while diving. Manta rays are also seen at the right time of the year, and other sharks can include the bull, hammerhead, silky and dusky varieties.
Most dives are drifts, and on one 40-minute dive we travelled 1.5 miles across the shoal and down the coast.

  • Blue Wilderness can arrange other exciting dive experiences and wildlife viewing around southern Africa, www.bluewilderness.co.za.

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    The one that got away - this shark still has a hook in its mouth.
    Sean dangles the shark bait.
    A tiger shark accompanied by remoras
    a typical beach launch