{"id":639,"date":"2017-05-01T17:16:55","date_gmt":"2017-05-01T16:16:55","guid":{"rendered":"http:\/\/www.josephcaruana.co.uk\/diving\/?p=639"},"modified":"2017-05-01T20:03:30","modified_gmt":"2017-05-01T19:03:30","slug":"tech-dive-at-ras-il-hobz","status":"publish","type":"post","link":"https:\/\/www.josephcaruana.co.uk\/diving\/2017\/05\/01\/tech-dive-at-ras-il-hobz\/","title":{"rendered":"Tech dive at Ras il-Hobz"},"content":{"rendered":"

On Saturday afternoon the wind changed and started blowing from the North. \u00a0We therefore decided to\u00a0dive the South coast,\u00a0opting for a deep 60-metre dive at Ras il-Hobz which would serve the purpose of being a simulation dive for an upcoming dive at\u00a0Bottleneck cave, whose exit lies at a similar depth. \u00a0We planned a bottom time of 25 minutes, as per the below. \u00a0For non-divers, first column is depth, second column denotes the plan, third column describes the schedule in case the dive is 3m deeper, fourth column gives the plan in case the dive is 3 minutes longer, and the last column is a contingency plan in the case of lost decompression gas (which means that the diver would have to complete their decompression using the bottom gas instead).<\/p>\n

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The dive plan.<\/figcaption><\/figure>\n

The scenery at Ras il-Hobz is really beautiful at the moment, with Spring colours popping out everywhere.<\/p>\n

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Pretty scenery at Ras il-Hobz<\/figcaption><\/figure>\n

Upon hitting the water, we proceeded without delay to our chosen depth, encountering a nice anemone along the way, of which I have pulled\u00a0a (very poor) still frame from some video footage I collected. \u00a0It should be remarked that the continuing problems with wastewater dumping\u00a0at this site has completely ruined the deeper regions; one hopes that the authorities get their act together sooner rather than later and address the very sad state of affairs.<\/p>\n

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Still frame of an anemone (pulled from video footage acquired at depth).<\/figcaption><\/figure>\n

When our bottom time was up, we proceeded with our ascent. \u00a0I readied the camera for a couple of pictures of the pillar that rises from the depths up to around 6m below the surface.<\/p>\n

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The pillar rising from the depths.<\/figcaption><\/figure>\n

Upon reaching the 21-metre mark, we changed to our decompression gas (50% O2). \u00a0As we off-gassed, we were entertained by various fish species, such as this shoal of Salemas.<\/p>\n

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Shoal of Salemas.<\/figcaption><\/figure>\n

Then, Brian gestured to me that he had spotted a photo opportunity. \u00a0So I proceeded to follow him around the corner, curious to find out what he had spotted…<\/p>\n

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Brian signs there’s a picture opportunity.<\/figcaption><\/figure>\n

He started\u00a0pointing at a very strange-looking thing which looked like, well… spaghetti!<\/p>\n

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Brian points at a peculiar feature.<\/figcaption><\/figure>\n

Upon moving closer to obtain a close-up shot, I realised it\u00a0was actually made up of many\u00a0tiny eggs… this most\u00a0peculiar\u00a0feature was none other than sea hare<\/a> egg-strings.<\/p>\n

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Sea hare eggs.<\/figcaption><\/figure>\n

Upon proceeding to shallower depths, I snapped a picture of the feature that earns this site the\u00a0name of “Middle Finger” amongst divers. \u00a0Just look at the picture below and you’ll see for yourself what I mean.<\/p>\n

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Middle Finger<\/figcaption><\/figure>\n

Ascending\u00a0to the last decompression stop at 3m, we\u00a0came across a large shoal of Barracudas, which made the remaining few minutes of deco whizz by.<\/p>\n

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Shoal of Barracudas making our final decompression stop a pleasure.<\/figcaption><\/figure>\n

As we completed our deco I did a few buoyancy & trim checks, with Brian kindly shooting some video footage for later reference.<\/p>\n

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During the last deco stop.<\/figcaption><\/figure>\n

And that was it! \u00a0A very pleasant dive, and my deepest one at that. \u00a0At 60m, a level of narcosis was certainly perceptible, but I felt it was very well manageable. \u00a0Of course, I have been building up to this depth level gradually over several dives. \u00a060 metres is where I draw a very hard line for air diving. \u00a0Below this depth, the PO2 (partial pressure of Oxygen) rises beyond 1.5. \u00a0While we regularly decompress at a PO2 of 1.6 (the maximum recommended) while breathing high O2 mixtures (at low work levels), the combined depth-related factors\u00a0of\u00a0(a) narcosis, (b)\u00a0increased density of the breathing gas, (c) higher chances of CO2 retention at depth, and (d) increased work, make me draw a line at this depth, beyond which I am definitely not willing to descend unless using Trimix. \u00a0(For non-divers, Trimix is a breathing mixture of Nitrogen, Oxygen and Helium, where the Helium replaces some of the\u00a0fraction of Oxygen (21%) and Nitrogen (78%) in normal air.)<\/p>\n

We had another dive planned for the following day, so watch this space for another post soon! \u00a0In the meantime, here goes the actual profile for this dive as recorded by the Shearwater Petrel 2 dive computer. \u00a0Stay tuned!<\/p>\n

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Dive-profile<\/figcaption><\/figure>\n