Alca

2018-08-26
Sunday afternoon and evening trip of diving club Kupla with our boat Hinkki.
We were 6 divers: me, Vode, Juho, Juha K, Tommi, Mikko V. Juho and Tommi were diving CCR.
We left harbor as planned at 13:00.

Initial plan was to dive T-54 Kljuts, a WW2 Soviet war wreck. The weather was a bit cooler than last weeks, only 18 deg-C, it was cloudy, windy and waves were getting big. Hinkki boat was unable to reach proper cruise speed, only 15 knots at 4000 RPM. Later inspection of the bottom revealed that there was thick layer of barnacle attached to the boat (Amphibalanus improvisus), hence there was significant drag to the boat. After one hour of driving towards east, near the Söderskär lighthouse the waves were getting really big, and we concluded that diving T-54 would be too risky in this weather. We decided that the wreck of Alca, which was nearby would be a safer choice. Alca has a fixed buoy, so we could attach the boat straight away, and surface operations would be much safer.

So Alca it was. At Alca bottom is at 45 meters, most of the wreck can be dived at 35 to 40 m. T-54 would have been 55 m deep.
We decided to dive into two teams of three. First into the water went me, Vode and Juha, all of us diving with OC and Trimix 21/35. Me and Vode D12, Juha D18. We all took just EAN50 deco tanks. Plan was to do 30 min at bottom, total dive time 60 min max. Juha would take a camera. I decided not to take camera, as I has been at this wreck 2 weeks ago already. I changed to my dive light a narrow beam 10 degree lens.

Weather was quite rough, so went down quickly. Surface water was still quite warm 17 deg-C, but at 15 meters there was a sharp thermocline, deeper the water was 4 deg-C. When we reach the wreck, the visibility was really good, much better than 2 weeks ago, about 10 meters vertical, and we could see the entire rear deck. We first descended to look at the propeller and the rudder. Then along the right side to the bow, where you could now clearly see how it was broken due to hitting a mine. Then back on the left side. We stopped at the skylets of the engine room for quite a while, as now you could really see down to the engine. But the engine is a bit too small to enter with twin tanks. You also see clearly the name of the boat on the left side at rear. After 28 minutes we had pretty much seen everything, so decided to star ascent. Everything went as planned, without incidents. It was a nice dive.

Next into water went the CCR divers and Mikko with OC. CCR divers took two bailouts each, Mikko has OC, and 3 stage tanks. Their plan was 40 min bottom, total 80 min. They also dove their plan to the minute, no issues.

At 17:50 we started driving back. Weather was getting just worse, and it was a rough ride. We stopped at Kaivopuisto to refuel, 99 liters of diesel = 164 EUR => 27 EUR / diver.
We had planned to have pizza at Skiffer, but it was closed due to bad weather. So skipped pizza and drove back to harbor. As soon as we got back to harbor, ti started to pour rain. It was nasty to unload the boat.

Back at Kuplakammio at 19:00.
So I decided to refill my tanks. I topped the D12 with TMX 21/35 by CFM. Refilled the Alu7 with 50% O2, and topped the suit gas tank. Total cost of fills: 29 EUR for Trimix, 6 EUR for EAN50 = 35 EUR.