Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 60; Flight Crew Total 10100; Flight Crew Type 2000
Situational Awareness
Ground Excursion Runway; Inflight Event / Encounter Weather / Turbulence
General None Reported / Taken
Environment - Non Weather Related; Weather; Human Factors
During landing an over-run occurred. The weather reported winds of 190 at 8 knots; with variable direction.  We were stabilized before the final approach fix.  Upon landing the wind switched to a right crosswind (less than 10 knots).  I applied max thrust reverse and moderate braking. Because of unforeseen standing water the anti-skid was activated and minimal braking was possible and we also encountered hydroplaning.  We exited the end of the runway into a dirt clearway at a very low speed; approximately 5-10 knots. Hard compact dirt allowed me to stop the aircraft within about 10-20 feet. No damage occurred. The aircraft was towed back onto the taxiway.
[Report narrative contained no additional information.]
Gulfstream flight crew reported hydroplaning during their landing rollout which led to a runway overrun.