Clean it up and change the oil. Run it a few minutes, then change it again. Take a look at the oil now- any signs of water? If so, repeat. If not, ride it a bit and continue checking the oil for signs of water.
I'd expect at only 18" you probably won't have too much trouble.
'06 Speed Triple
'96 Adventurer Cafe Racer
and a bunch of other stuff
If everything seems under control, you're just not going fast enough - Mario Andretti