Small white ball 2" diameter hovering in the ocean with 4" diameter blades.6:40 a.m. In fishing trip at exactly lat=9.54548056158, lon=-84.7876647133, Puntarenas, Costa Rica. We both saw one hovering white ball, similar in size as a ping pong ball, about 20 feet away from the boat. When we approached it, up to 10-15 feet, it slowly went up and flew above us, we both clearly saw the blades coming out from the middle of the sphere, they measured around 4' in diameter. The UFO flew for approximately 1 min. We couldn’t hear anything probably because of the noise from the outboard engine.