Boat from Summer Palace to Yuyuantan Park or Beijing Exhibition Centre

I've seen details on how to take the boat TO the summer palace but we are arriving by car to the summer palace and would like to take the boat FROM the summer palace back to the city. Is this possible? Or even worth it? Is it easy to find the pier when in the summer palace? I don't see it listed on any maps. We'd rather end up at the Exhibition Centre rather than Yuyuantan Park as it closer to our hotel and we don't want to end up in the Zoo as I don't want to pay for the zoo.