This story reminds me of the old comedy routine where the guy goes to the
doctor an says, "Doc, when I move my arm like this it hurts."  The doctor's
advice is so simple it is funny, "Don't move your arm like that!"

So my first suggestion would be to avoid driving through creeks if this is at
all possible.  I know that whenever I drive by a river, creek or ocean there
is always this sudden urge to drive the van right into the water (this can be
dangerous on bridges :).  We have to resist these primal urges for the sake
of our vans though as they weren't really made to be a submarine (watching
too many "Herbie the love Bug" movies?)

Seriously, you are having a electrical problem.  It is probably either a
partially deteriorated ground connection, bad plug wires, or a distributor
cap that needs to be replaced.  If you have to drive through tributaries you
might want to check these items out.  You could try to put some silicon where
your distributor cap goes on the distributor (might help some).  But again,
the best advice I can give is to not move your arm like that.  

Happy Friday!
Ken Wilford
Van-Again
John 3:16
http://www.vanagain.com
Office: (856)-765-1583
Fax: (856)-327-2242