You need to get water out of the plug holes. You can remove the cop's and blow the water out with an air hose or if your engine runs let it idle for about 30 minutes.
The air hose method might prevent damage to the COP boots that could occur due to arc'ing.
I do not know beans about the length of time required for water in the spark plug hole to cause boot damage in a running engine.
See this thread...
Water in coil?
1999 Ford F150 Lariat Flareside Extended Cab, 4x4, 5.4L engine.