What really determines if data will be recoverable or not? We can replace melted PCBs. We can replace damaged head assemblies. We can rebuild missing NVRAM data. But it is the condition of the disks or platters that are most important when determining the chances of successfully recovering the data on any damaged hard drive. Water damaged drives are no exception. Letting the drive dry out is the worst scenario as mineral deposits from the water will embed themselves onto the disks and prevent a successful recovery. To prevent these deposits from forming on the disks as the water dries, keep the disk drive wet and sealed in a plastic bag and get it to a professional data recovery company ASAP. If the you fear it is already drying out, add some de-ionized or distilled water Expect fees of anywhere from $1400-3400 or even much more.