Complex sentence: As the wave strikes the beach it will first come into contact with the cusp horns, which will slow the water down this causes it to lose energy and some of the heavier sediment that its carrying will be deposited.
Split into simpler sentences: As the wave strikes the beach, it will first come into contact with the cusp horns, which will slow the water down. This causes it to lose energy and some of the heavier sediment that it is carrying will be deposited.