How do I filter the ocean water?
Pick a spot of low wet flat sand and dig a trench. make sure the trench has a mound in the centre with small hole in the center. Place the windbreaker over the hole. Then place the water proof sail over the trench and put a rock in the middle to create a centre weight.  Pour sea water over the the sail. As the sun hits the beach the water within the sail will try to evaporate. The sail is waterproof the water will collect underneath the sail as condensation. The  droplets will get bigger and heavier throughout the day they will fall towards the middle. This water will dribble down into the bowl made out of a waterproof windbreaker.