Location: Catalina Island, California USA
Comments: Eureka Platform sits in around 500 feet of water which makes it an oasis in the ocean desert. After getting permission from the platform thanks to the help of Captain Mike (is it a rule that all Captains get renamed Mike?) of the supply vessel Isabel El, we staged two dives here and the general consensus was that it was well worth the skiff ride. There is a very definite vertical line as you descend where the mussels leave off and the anemones take over at about 30 feet. There is also a marked difference between the life on each of the legs which presumably is due to differing light conditions and water movement. Some legs were covered in strawberry anemones, others in the white metridium. In amongst the anemones were barnacles and small amounts of kelp, sponges and corals.
The amount of life was amazing, including fish that you would not normally associate with deep water. Each leg and cross bar is its own ecosystem. We were lucky and had perfect conditions, the visibility was good and there was no current or waves so everyone was able to explore to their heart’s content. Apparently at about 75-80 feet there was a thermocline, the temperature dropped to 51°F and the visibility opened up to 100 feet. However, most of us stayed in the slightly warmer water on the grounds that there was so much to see you didn’t need to have more than 2 feet of visibility and therefore the 30 feet that we had was plenty.
After the second dive we headed back to the north east edge of Catalina to Ship Rock. This stands out of the water and someone once thought that it looked like the sail of a boat, hence the name. The topography underwater included several smaller rocks that came up to the surface and many ledges and gullies. At around 20 feet there was a ledge covered in palm kelp and the water temperature was a warming 63°F which made up for the lower visibility. At 70 feet the water temperature was 54-55°F with 30 feet of visibility and many different species of nudibranchs in prolific numbers. A truly wonderful day of diving followed by a crab feast on the moon deck and an overnight run up to San Miguel Island.
Surface Weather: Air temperature 80°F, clear skies, calm, calm
Dive Conditions: Water temperature 55 – 63°F, visibility 10-30 feet