---
kind: "section"
citation: "33 C.F.R. § 181.21"
title: "33"
number: "181.21"
heading: "Purpose, applicability and effective dates."
url: "https://uscodex.org/cfr/33/181.21"
---

# §181.21. Purpose, applicability and effective dates.


This subpart prescribes the requirements for identification of boats to which section [46 U.S.C. 4301](/usc/46/4301.md) applies.


## Notes

### Amendments

[CGD 79-013, 48 FR 40718, Sept. 9, 1983, as amended by USCG-1998-3799, 63 FR 35534, June 30, 1998; USCG-1999-5832, 64 FR 34716, June 29, 1999]

### Source

Source: CGD 79-013, 48 FR 40718, Sept. 9, 1983, unless otherwise noted.

### Authority

Authority: 46 U.S.C. 4302; DHS Delegation 00170.1, Revision No. 01.4.

### Source

Source: CGD 72-60, 37 FR 15779, Aug. 4, 1972, unless otherwise noted.

### Amendments

[CGD 79-013, 48 FR 40718, Sept. 9, 1983, as amended by USCG-1998-3799, 63 FR 35534, June 30, 1998; USCG-1999-5832, 64 FR 34716, June 29, 1999]