Patrolling in a boat with twin 300-horsepower diesel engines, Wolstad ensures that the commercial fishing boats in his jurisdiction are operating legally. The boat has a fully rigged "crab block" to pull up crab pots and determine their legality. A fire pump with hose can fight fires on other boats, and a portable pump is equipped to assist flooded vessels. An on-board microfiche reader is used to determine a boat's owner. For covert operations, Wolstad uses an 18-foot Boston Whaler with a 140-horsepower outboard engine. Of the 200-300 cases Wolstad initiates each year, most of the defendants plead guilty. The six to eight cases that went to trial last year all produced convictions.