Can a boat be flushed while it is in the water (salt water) using the flush kit that the dealers install? I always thought the boat had to be out of the water so that it wouldn't suck up saltwater at the same time, but a friend of mine, who worked for a dealership, said that it can be flushed in the water because the water pressure from the hose wont let the engine suck in any salt water. Is this true or does it have to be out of the water?

That would depend on how much water pressure you have in the hose. The raw water pump sucks up ALOT of water so I wouldn't do it.

It depends on which flush kit you have installed. I haved the flush pro and the answer is "yes".

yea, you can do it as long as the dock has good water pressure.I don't know what kind of flush kit you have, but on my boat i have a butterfly valve to shut off the raw water intake, then the hose connects in front of the valve, no way for salt water to get into the system while the hose is on.