Final answer:
The legal limit for intoxication when operating a vessel in Texas is a BAC or breath alcohol concentration of 0.08%. A Breathalyzer is used to determine the level of intoxication.
Step-by-step explanation:
In Texas, the legal limit for intoxication when operating a vessel is a blood alcohol concentration (BAC) or breath alcohol concentration of 0.08% by volume. Operating a vessel with a BAC at or above this level is considered legally intoxicated. The Breathalyzer is a common tool used by law enforcement to measure the ethanol concentration in a person's breath, which correlates with BAC. However, it is important to remember that depending on individual factors such as weight, gender, and rate of alcohol metabolism, the effects of alcohol can vary significantly between individuals, even at lower BAC levels.