An Cosantóir

sport | 31 the western side of the peninsula. We passed South Shetland, through the Gerlache Strait and down below the Antarctic Cir- cle, where it was expected the ship would encounter thicker ice and eventually be forced to turn back. This eventually occurred in the vicinity of Adelaide Island and Arrowsmith Peninsula. Prior to disembarking and actually being allowed to visit Antarctica all items of clothing and footwear, including all of our dive kit, was screened and vacuumed (mandatory procedures under the treaty that governs any Antarctic travel) to remove any foreign seeds, bugs, or even animals, that could contami- nate the environment or introduce new species that could affect the ecosystem. The ship continued south and eventually as we neared the ice the mandatory check-out dive was carried out by our polar dive guides. The nearest decompression chamber for a 'bend' was over 800 miles north at this stage and while there were two doctors on board, one a specific decompression specialist for the divers, it would be a long painful wait for a helicopter and an even more painful experience when the bill arrived! The water was colder than anywhere I'd dived previously, in- cluding the Arctic trip. All the diving equipment carried required backups, due to the extreme temperature it would be operating in. Although the average water temperature of between -200 and -400 C C may not sound too bad, when you are immersed in it under the ice for up to 24 minutes - the longest dive I man- aged to achieve - it becomes very obvious why your kit needs to be freeze protected and why you need so many thermal layers under your dry suit. Face and hands were the only areas that were not freeze protected, with the result that any metal in the dive kit tended to freeze to face and lips, leading to some painful experiences when trying to take kit off! However, this problem was alleviated by applying a coating of Vaseline to the areas of exposed skin. The freezing of kit while on the dives was a major safety issue as malfunction or failure at depth could have serious conse- quences. Consequently, every diver was required to carry a large amount of surplus and replacement kit, which accounted for the large excess baggage charges involved on the trip! Malfunctions occurred primarily due to ice forming on the in- side of various items of kit. The water temperature also caused computers to fail due to the effects of the cold on the batteries. Even with the layers the intense cold affected co-ordination and dexterity, which was a limiter on your dive time as the sensation loss meant malfunctions could not be dealt with properly. Following the check-dive we proceeded to the first proper ice dive at Cuverville Island. Prior to any dive an ice assessment has to be carried out, which takes into account air and water temperatures, current strength and the ice condition itself. If an iceberg is being dived, its size, structure and erosion dam- age visible all need to be considered. If the ice assessment is bad then another berg is sought out, as an iceberg collapsing or moving, or indeed turning over as occurred during one dive, can be a little disconcerting! The ideal icebergs were those that had beached and were stuck fast due to their size as these allowed us more freedom to dive them through and around them. To be continued... THE DEFENCE FORCES MAGAZINE

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