These boats are made out of Brazilian hard wood. They are very heavy and to pick up and move. It will take ten men to move one of these small boats. They are very durable and can stay out on the river day and night without a problem. What happens when you fill them with water. Well they float just below the level of the water. How do I know that, from experience! The last boat we had like this we did sink the boat near the beach. The waves poured in and filled the boat to the top with water. It did not stay on the beach but floated off the beach. Now my aluminum boat will not float! It sinks to the bottom of the beach and it took a good crew to bail the water out and float her. Pray for out safety.