Bees!! And lots of 'em!!

[The Raddish]

Well, we have sprayed and sprayed and sprayed, and seem to have kept them at bay now. There are a few stragglers once in a while that are attracted to our ladder for some reason, but we're talking only a couple per day, and we can handle that.

Aside from that, we had a storm blow through a few days ago and that seemed to clear a lot of them out also.

[matt4x4]

And all over your pool only? Something about your pool is attracting them, I know bees are always in need of water, maybe bump the chlorine level by a bit for a while, they may hunt down another pool nearby with a lower level then.
If you don't have a nest anywhere nearby, look at your trees and neighbouring trees, some nests are hard to spot when they are using the actual tree as a nest - you will see some spots on the tree covered in bees where they enter/exit the hive (hollow tree or branch).

[mbar]

last year I had the same problem with wasps. One day I watched to see where they were going - they had a nest built underground in some rocks I have on the bank next to the pool. I had the exterminator come and spray the whole bank, and the wasp problem went away. Sit quietly and see where they are flying to and from - I bet you will see a nest nearby.