---
kind: "section"
citation: "46 C.F.R. § 170.285"
title: "46"
number: "170.285"
heading: "Free surface correction for intact stability calculations."
url: "https://uscodex.org/cfr/46/170.285"
---

# §170.285. Free surface correction for intact stability calculations.

- (a) When doing the intact stability calculations required by this subchapter, the virtual increase in the vessel's vertical center of gravity due to liquids in tanks must be determined by calculating—
  - (1) For each type of consumable liquid, the maximum free surface effect of at least one transverse pair of wing tanks or a single centerline tank; and
  - (2) **The maximum free surface effect of each partially filled tank containing non-consumable liquids.**
- (b) For the purpose of [paragraph (a)(1)](#a-1) of this section, the tank or combination of tanks selected must be those having the greatest free surface effect.

## Notes

### Authority

Authority: 43 U.S.C. 1333; 46 U.S.C. 2103, 3306, 3703; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; Department of Homeland Security Delegation No. 0170.1.

### Source

Source: CGD 79-023, 48 FR 51010, Nov. 4, 1983, unless otherwise noted.