David, It could be a couple of things. Do you have an adjustable water regulator for your park water? Also you might check your filter or filters. Sometimes they can plug up pretty fast. There could also be a kinked hose if your shower is in the slide. Make sure your outside faucets in your water bay are turned off. Cant explain why, but those being left on effects your incoming  water pressure. Lastly, if you are not a member of DOAI, (Discovery Owners Association) I would suggest joining up. Great organization with many very knowledgeable Discovery owners answering questions such as water pressure on the forum. They have helped many D owners with all kinds of problems. Second to none. If you would like more info about DOAI, feel free to contact me off forum.

Jim Pinkerton