This is the dramatic moment when German police rammed a dinghy carrying demonstrators at the summit.
Police motor launches clashed with two Greenpeace inflatables following a high-speed chase across the Baltic Sea.
Meanwhile, on land, thousands of demonstrators continued to try to disrupt the day's meetings by blocking roads, despite bursts of water cannon and tear gas and numerous arrests.
The ten-minute pursuit on the high seas was beamed by satellite TV around the globe.
Greenpeace protesters were aiming to score a publicity coup by breaching the massive security and reaching the luxury summit hotel in the resort of Heiligendamm - and they nearly succeeded.