As the water begins to get shallower, water movement is slowed by friction against the bottom. The waves are slowed down and pushed together. That makes each wave steeper, especially on its front side. As the water gets shallower, the waves get steeper and steeper until they fall over and break on the front side.
While bees and wasps inject venom when they sting, mosquitoes simply bite to feed on your blood. The bumps and itchiness that follow come from an anticoagulant that the mosquito injects to prevent your blood from clotting, which triggers a mild allergic reaction that includes the typical round, red bumps.