Water Temperature and Visibility
Depending on location, the sea surface temperature can reach a low of around 50°F (10°C) in the winter months and may get up to 75°F (24°C) in the late summer. At depth the water temperature can range from a low of 48°F (9°C) to a high of 72°F (22°C). In general the water temperature becomes colder to North and warmer to the South. Santa Catalina and San Clemente islands are usually the warmest sites, with San Miguel island always the coldest because of the deep water upwelling at Point Conception.
Most divers wear a full 1/4″ (7mm) thick or equivalent wet suit year round, with full hood, boots and gloves. Some divers even wear dry suits with a minimal undergarments in the summer and thicker ones in the late winter. A shorty or thin “warm water” suit just doesn’t cut it in our waters, especially during our live-aboard trips where you’ll be making many repetitive dives. If visiting from out of the area, we can refer you to a local dive shop and help make arrangements to rent gear such as suits, tanks and weights.
Locally, water visibility is considered to be poor when it is 30′; average when 60′; and great when some sites will see 80′ to more than 100′. The best visibility occurs in fall and winter months, so long as we don’t have any heavy rain which can cause run-off and worsen visibility. Summer months are great to enjoy the warm surface temperatures and get a good tan. However as the water warms up plankton will bloom slightly reducing visibility. Even though, summer diving is still excellent and very pleasant time to visit. Our personal favorite time of the year to dive is October, when the water is the warmest it gets, visibility is good and it is also bug season! It makes for perfect night diving conditions.
Southern California’s air temperatures are mild and reach in the high 70’s to 80’s, possibly higher, during the summer months. Winter temperatures can drop down to a brisk (by our standards) 60’s. Bring a light jacket or windbreaker for evenings because on the water the nights can cool down and you may get chilled. Some will bring sleeping bags to cozy up in after a long day of diving. Summers are great for sunning on our spacious sun deck and even winter days have sunny or hazy overcast days. Bring sun protection any time of the year.
Sometimes the seas are flat calm, even up to 80 miles offshore. And sometimes the seas get a bit rough. Given the unpredictable disposition of mother nature, our trip destinations are not guaranteed. Rarely are trips canceled due to bad weather. Do not “assume” that a trip is canceled is the weather outside is poor. At times when it is raining onshore the sea may be dead calm. Often, we will divert to a calmer spot, or tuck into the lee of one of the islands. This decision is at the sole discretion of the captain. Weather conditions can change dramatically in just 24 hours.