Designated Duty Engineer. This is an advanced-level merchant mariner credential. The general requirements for this credential are TWIC Card (Identification, Fingerprints, Citizenship, Social Security number, etc), CG-719B Application, NDR Consent & Check, Oath, 3 letters of recommendation, photograph (supplied by TSA), SSEB Screening complete, age of 21 or over, CG-719K Physical Exam, Medical Tab in MMLD, Drug Testing Compliance, Mariner Fees, and Sea Service Letters or Discharges. Sea service requirements include recency- 90 days in the past 3 years on vessels of appropriate horsepower. DDE- AHP, 1080 days of service in the engine room, with 540 days as a QMED or equivalent supervisory position. DDE- 4000 HP, 720 days of service in the engine room, with 360 days as a QMED or equivalent supervisory position. DDE- 1000 HP, 360 days of service in the engine room, with 180 days as a QMED or equivalent supervisory position. Service gained in the deck department on vessels of appropriate tonnage may substitute for up to 25% or 180 days (whichever is less) of the required service. There are also propulsion requirements. Other requirements include Basic Safety Training; or Continued Competency in BST, Flashing Light- course, and a valid, approved radar observer course. All candidates must complete an examination.