---
kind: "section"
citation: "33 C.F.R. § 183.620"
title: "33"
number: "183.620"
heading: "Natural ventilation system."
url: "https://uscodex.org/cfr/33/183.620"
---

# §183.620. Natural ventilation system.

- (a) Except for compartments open to the atmosphere, a natural ventilation system that meets the requirements of [§ 183.630](/cfr/33/183.630.md) must be provided for each compartment in a boat that:
  - (1) Contains a permanently installed gasoline engine;
  - (2) Has openings between it and a compartment that requires ventilation, where the aggregate area of those openings exceeds 2 percent of the area between the compartments, except as provided in [paragraph (c)](#c) of this section;
  - (3) Contains a permanently installed fuel tank and an electrical component that is not ignition protected in accordance with [§ 183.410(a)](/cfr/33/183.410.md?p=a);
  - (4) Contains a fuel tank that vents into that compartment; or
  - (5) **Contains a non-metallic fuel tank—**
    - (i) With an aggregate permeability rate exceeding 1.2 grams of fuel loss in 24 hours per cubic foot of net compartment volume, or
    - (ii) If the net compartment volume is less than one cubic foot, having a permeability rate exceeding 1.2 grams of fuel loss in 24 hours.
- (b) Each supply opening required in [§ 183.630](/cfr/33/183.630.md) must be located on the exterior surface of the boat.
- (c) An accommodation compartment above a compartment requiring ventilation that is separated from the compartment requiring ventilation by a deck or other structure is excepted from [paragraph (a)(2)](#a-2) of this section.

## Notes

### Amendments

[CGD 76-082, 44 FR 73027, Dec. 17, 1979, as amended by CGD 76-082(a), 46 FR 27645, May 21, 1981; CGD 85-059, 51 FR 37577, Oct. 23, 1986; USCG-1999-5832, 64 FR 34716, June 29, 1999; USCG-1999-5151, 64 FR 67176, Dec. 1, 1999]

### Source

Source: CGD 76-082, 44 FR 73027, Dec. 17, 1979, unless otherwise noted.

### Authority

Authority: 46 U.S.C. 4302; Pub. L. 103-206, 107 Stat. 2439; and Department of Homeland Security Delegation No. 0170.1, para. II, (92)(b). Subpart E is also authorized by Pub. L. 114-120, 130 Stat. 27

### Source

Source: CGD 72-61R, 37 FR 15782, Aug. 4, 1972, unless otherwise noted.

### Amendments

[CGD 76-082, 44 FR 73027, Dec. 17, 1979, as amended by CGD 76-082(a), 46 FR 27645, May 21, 1981; CGD 85-059, 51 FR 37577, Oct. 23, 1986; USCG-1999-5832, 64 FR 34716, June 29, 1999; USCG-1999-5151, 64 FR 67176, Dec. 1, 1999]