Blue "By-the-wind sailor" jellyfish

I noticed a line of purple in the surf line yesterday morning while walking along a high beach trail, but just thought it was some kind of drying see grass from a distance. Today, I went down to the beach and there were tens of thousands of Velella velella, mostly dead (desiccated and clear) and some that were still hydrated and colorful washed up on the beach in three distinct lines of where the tide had reached in the last 24 hours.