Do I need to wear a helmet?

YES!

I would like to say that I was shocked with the amount of motorbike accidents but I am not. How many accidents are not reported?

View Accident black spots in a larger map

This is a map of some of the reported road tragedies.

I would suggest to any visitors to Thailand that unless they normally ride a motorbike not to rent one here.

BUT if you do - please rent a helmet.

Thanks to the Phuket Gazette for informing us.