pump very hard to make a BIG gush of water, I can get the inside of the top lid and part of the seat wet.

I talked to a number of friends who also had been using the Lavac for some time. On their recommendation, I ran the vacuum break inside the head and removed the small rubber flapper valve in it. To flush, I hold a finger over the opening where the flapper was. Then remove my finger and pump a couple of more times. It's than ready for the next use, no waiting!.

I also followed the directions that came with it so the same pump works for flushing the Lavac AND pumping the holding tank when far out at sea.

Greg