I would imagine some sort of test involving safety equipment such as life boats, jackets, fire extinguishers and similar- and the Coast Guard has the right of inspection.
See
By operating a boat in Georgia, you have consented to a sobriety test if directed.
Sobrity
sobriety
Sobriety Test
Sobriety Test
Sobriety test
That would be the 'sobriety test', Cap'n!
sobriety test
Sobriety
sobriety
A Field Sobriety test will determine Blood Alcohol Content (BAC).