🔍 Key Concepts

• Fresh water vs. salt (sea) water density and how that affects draft • The standard "fresh water allowance" or FWA correction in feet per foot of draft • How to apply the 1.025 specific gravity of seawater in common exam shortcut formulas

💭 Think About

• Should a vessel sink deeper or rise higher when going from fresh water to sea water? Why? Think about which liquid is denser. • Start from the given 20 ft draft in fresh water. About how much does the draft usually change per 10 ft of draft when moving between fresh and sea water? • Estimate the correction amount and then compare it to the answer choices to see which one is closest.

✅ Before You Answer

• Be clear on whether you are adding or subtracting from 20 ft when moving into sea water. • Use the approximate 2.5% difference in density between fresh water (SG 1.000) and sea water (SG 1.025) as part of your mental math. • After you adjust the draft, check that your new draft is reasonable (a small change, not several feet).