(a) “Alcohol concentration of 0.08 or more” shall mean:
(1) An amount of alcohol in a sample of a person's blood equivalent to 0.08 or more grams of alcohol per 100 milliliters of blood; or
(2) An amount of alcohol in a sample of a person's breath equivalent to 0.08 or more grams per 210 liters of breath.
(b) “Chemical test” or “test” shall include any form or method of analysis of a person's blood, breath or urine for the purposes of determining alcohol concentration or the presence of drugs which is approved for use by the Division of Forensic Science, the Delaware State Police Crime Laboratory, any state or federal law-enforcement agency, or any hospital or medical laboratory. It shall not, however, include a preliminary screening test of breath performed in order to estimate the alcohol concentration of a person at the scene of a stop or other initial encounter between a law-enforcement officer and the person.
(c) “Operating a vessel or vessel operation” shall include driving, operating or having actual physical control of a vessel or boat.
(d) “Prior or previous offense” shall mean:
(1) A conviction pursuant to this chapter, or a similar statute of any state, local jurisdiction or the District of Columbia, within 5 years immediately preceding the date of the present offense; or
(2) A conviction, under a criminal statute encompassing death or injury caused to another person by the person's operation of a vessel, where operating a vessel under the influence or with a prohibited alcohol concentration was an element of the offense.
For the purpose of computing the periods of time set out in § 2305 of this title, the period shall run from the date of the commission of the prior or previous offense to the date of the commission of the charged offense. In any proceeding under § 2305 of this title, a person may not challenge the validity of any prior or previous conviction unless that person first successfully challenges the prior or previous conviction in the court in which the conviction arose and provides written notice of the challenge in the present proceeding to the prosecution at least 20 days before trial.
(e) “Underway” shall be defined as any vessel which is not at anchor or made fast ashore.
(f) “Vessel” shall mean every device in, upon or by which any person may be transported upon the water excepting devices moved by human power.
(g) “While under the influence” shall mean that the person is, because of alcohol or drugs or a combination of both, less able than the person would ordinarily have been, either mentally or physically, to exercise clear judgment, sufficient physical control, or due care in the operation of a vessel or boat.