Investigators have concluded MLB pitcher Jose Fernandez was driving his boat at the time it crashed in Miami ... killing everyone on board ... and say he was drunk and high on cocaine at the time.
Fernandez -- along with Emilio Macias and Eduardo Rivero -- were killed on Sept. 25 when Jose's boat smashed into a jetty around 3 AM.
The FL Fish and Wildlife Conservation Commission launched an investigation into the incident -- and Thursday, they released their findings.
Long story short ... Fernandez's blood alcohol level was almost twice the legal limit and his blood tested positive for traces of cocaine.