There really are no "sandy" beaches. The entire island consists of dead coral. Most beaches look like boneyards. No coral nor shells may leave the island. The surrounding water and reefs is a protected marine preserve. You can collect shells and coral from the beaches, but you must leave your find on the island.
Klein (meaning "little") Bonaire is a satellite island. There is no settlements there, but does have a few real sand beaches for picnics. But great caution is taken if you step foot on the beaches because the island itself is a protected sea turtle habitat. Hawksbill, green and leatherback turtles all use the island to lay eggs on.
The 1st picture and last picture of the post are almost the same. In the bottom pic, I've colored our condo and the areas we found to be the very best snorkeling. A swim around the point to the left or swim across the channel and around the point straight across and to the right. The channel is for private and commercial boats in that marina. The end of the runway is right behind our house, but we really never heard the jets come and go. Notice the pink airport in the top pic?