From Loggingin2012
You must obtain a Transportation Worker Identification Credential (TWIC). The TWIC was established by Congress through the Maritime Transportation Security Act (MTSA) and is administered by the Transportation Security Administration (TSA) and U.S. Coast Guard. TWICs are tamper-resistant biometric credentials issued to workers who require unescorted access to secure areas of ports, including all Merchant Mariners. To obtain a TWIC you must go to a TSA enrollment center twice, once for enrollment, the second time to pick up the TWIC. Enrollment and pick-up must be done at the same enrollment center. Once you enroll, there may be a six to eight week wait to pick up the TWIC, so enroll early. The cost of the TWIC is currently $132.50. Proof of obtaining a TWIC may be demonstrated to the Academy in several ways, listed in priority order:
(1) Mail the TWIC to Midshipmen Personnel along with your Passport prior to your arrival.
(2) Surrender the TWIC during in-processing at the Academy.
(3) Show proof of enrollment for a TWIC during in-processing at the Academy by providing a copy of the receipt from the enrollment center if you have not yet been notified that the TWIC is available for pick-up. The student in this case will have to pick up the TWIC at the first opportunity (e.g., authorized leave period in which the student travels to the vicinity of the enrollment center), then surrender the TWIC to Midshipmen Personnel.
(4) Provide a written statement to Midshipmen Personnel during in-processing that states the nearest enrollment center was more than 200 miles from your home and/or would have represented a significant burden on the student or family to enroll for a TWIC prior to reporting. In this case, the Academy will arrange for the student to obtain the TWIC some time during the academic year at the New York City enrollment center. The student must provide the funds to pay for the TWIC, either credit card or check (no cash).
NOTE: Foreign students do not have to obtain a TWIC prior to reporting to the Academy. They will be processed for a TWIC during the academic year.
I contacted Admissions about a month ago and they confirmed that they will follow the same process this year.