Red tide is the generic name for an algal bloom regardless if it is red or not. Many algal blooms are harmful as they reduce oxygen concentrations in the water and also contain toxins that can accumulate in filter feeders. Some harmful algal blooms can cause skin irritation, but I haven't noticed that with the Monterey variety. Getting a little in your mouth is not the end of the world, where it becomes a problem is if you eat any filter feeders (shellfish, etc) that have been eating the algae for a while. You could get a concetrated dose, which is not good. When the red tide is around, it can normally be found from Del monte beach to Otter cove. It usually is sits in the top 20-40 feet of water, so you can get under it if there is enough depth. Since it usually lowers the oxygen level in the water, fish tend to leave the area.
So take a hint from the fish. Stillwater cove, Monastery and Pt. Lobos should be nice all week.