50 CFR §218.237

1. (a)To incidentally take marine mammals pursuant to these regulations, Navy must apply for and obtain a Letter of Authorization (LOA).
2. (b)An LOA, unless suspended or revoked, may be effective for a period of time not to exceed the expiration date of these regulations.
3. (c)If an LOA expires prior to the expiration date of these regulations, Navy may apply for and obtain a renewal of the LOA.
4. (d)In the event of projected changes to the activity or to mitigation and monitoring measures required by an LOA (excluding changes made pursuant to the adaptive management provision of § 218.239), the Navy must apply for and obtain a modification of the LOA as described in § 218.238.
5. (e)The LOA shall set forth:
   1. (1)Permissible methods of incidental taking;
   2. (2)Means of effecting the least practicable adverse impact on the species, its habitat, and on the availability of the species for subsistence uses (i.e., mitigation); and
   3. (3)Requirements for monitoring and reporting.
6. (f)Issuance of the LOA will be based on a determination that the level of taking will be consistent with the findings made for the total taking allowable under these regulations.
7. (g)Notice of issuance or denial of an LOA will be published in the Federal Register within thirty days of a determination.