Posted by Eric Frasco on August 16, 2001 at 12:59:51:
In Reply to: oops, sorry, how about LA area...channel islands, etc. posted by robin on August 15, 2001 at 14:41:42:
Robin:
The Channel Islands help protect the stretch of coastline from Point Conception to San Diego by deflecting a lot of the incoming swell and wind driven waves, making for good diving year round. the rest of the coastline (total coastline is approximately 1150 miles) is exposed to open ocean conditions, making for rough conditions year round.
From Santa Barbara to Laguana Beach, September and October are when we have the warmest and clearest water.
San Diego water temps always seem (to me) to be colder, I will let someone from San Diego comment on that. North of Santa Barbara, you have a prevailing southerly colder current that generally runs outside the Channel Islands. There is a warm northerly current that comes up along the Los Angeles coastline, and mixes with the colder current at the Northern Channel Islands (NCI). So diving at the NCI can be cold if you are on the western islands such as San Miguel or Santa Rosa, or warmer if you are at the eastern islands such as Santa Cruz or Anacapa. At any rate, all the diving up there is great because the two currents coming together have created an excellent habitat that supports an abundance and variety of marine life.
But on the mainland the best beach diving is in September and October. The ocean temperature starts to peak (it takes a couple months for water temperatures to catch up with air temperatures), but most importantly the visibility gets really good. Plankton blooms, which depend on sunlight, are a big culprit in reducing visibility. During the long days of summer (summer soltice in June), there is lots of sunlight, and therefore lots of plankton. By September, the days have shortened and the plankton blooms are significantly reduced.
So there's your answer. In the areas around Los Angeles, the best visibility and the warmest water occurs in September and October. It is not unusual to have 70 degrees F and 100 foot visibility at the Southern Channel Islands (Santa Catalina, San Clemente) this time of year.
-Eric-