Question:
I have low-water pickups on my Bravo I's. Last weekend, at idle forward, I grounded a bit on a muddy bottom.
Should I have taken any measures to ensure no damage ?
Or - no worries ? I flushed the motors upon return to my slip.

Yeah, what he said above. I filled my motor with sand twice last year due to those damn low water pickups. I hate them. I'm thinking of adding the mid section holes like a standard drive has....see my other post about doing this. Take the hoses that go to and from your sea water pump off and check for mud. Do the same with the hose from the oil cooler to the circulating pump. Remove the freeze plugs too....see if there is any mud in the block. Also, if you do find a lot of sand/silt/mud, you might want to check your impeller. I had one go bad on me due to sand ingestion. Sucks doesn't it???

'Foul

Pull all the hoses and flush them. Replace the impellers. I have seen them bad enough to block all water flow, the hoses hard and solid with mud.