Because it was raining, dark and other motorists were focused on ensuring he was not run over, no one managed to get a description of the fleeing vehicle as it drove off down Fraser St, he said.
Mr Watson believed the fleeing driver was a man.
Mr Watson said he was taken to Tauranga Hospital for observation and left with a thumping headache and was still suffering migraines. His motorbike was no longer rideable.
"I counted myself lucky my injuries are not far worse. We could well be talking about broken bones at the very least. I'm lucky to be alive. We all make mistakes but I want the driver to man up and come forward," he said.
Mr Watson said if the driver must be held to account it may well be a child next time and someone must know who it is as the vehicle would have a significant dent in the passenger side.
His pregnant partner Jasmine Douglas, who is expecting their first child in September, said when she learned Mr Watson was involved in the crash she "nearly had a heart attack".
She was also pleading with the driver to come forward.
Mr Watson said he wanted to send a big thank you to everyone who came to his aid.
Head of Western Bay road policing Senior Sergeant Ian Campion said eyewitnesses suggest the vehicle could be a small car, possibly a Ford.
"I urge the driver to come forward to speak to police about this matter and would also like any panel beaters who may have been asked to make some repairs to give us a call," he said.
Anyone with information is urged to call police on 577 4300.