We had the same concerns before going to CTI. On one side of the pool there are wonderful trees for shade. We never once had a problem with finding a shady spot as we don't lying in the sun either! Same thing goes for the beach, very comfortable with quite a bit of shade given by the trees.
We just returned from CTI. There are no umbrellas; however, there are areas with shade. The lounge chairs on one side of the pool were always shaded - the chairs on the other side had sun from about 8 am - 4 pm. The beach has palm trees which provides shade.
Ditto. At CSA the tiki huts are "reserved" early. We travel with another couple and while the guys are diving she likes to sun... I vaporize in sunlight. I can't hibernate under the palm trees if she's at waters edge.... hard to carry on a conversation that way! Planning to take a travel beach umbrella that weighs 5 to 6 pounds and folds to 2 feet. Wish Couples would consider umbrella rentals... not asking for a freebie.