🔍 Key Concepts

• Fresh Water Allowance (FWA) and what it represents on the draft marks • How draft changes in different water densities using the proportional relationship between density change and draft change • Difference in density between water of 1.010 and salt water of 1.025 and how that compares to the density difference used to define FWA

💭 Think About

• First, recall: FWA is defined for the change between salt water (about 1.025) and fresh water (about 1.000). How much density change does that 8-inch allowance correspond to? • Compare the actual density you have (1.010) to the standard fresh water and salt water densities. Is your current water closer to fresh or salt? • Set up a simple proportion: if X density change produces 8 inches, what draft change will result from the smaller density difference between 1.010 and 1.025?

✅ Before You Answer

• Be sure you are using the correct density differences (not just the raw densities themselves) when setting up your ratio. • Confirm whether the vessel will sit deeper or shallower in the current water (1.010) compared to salt water (1.025). • Check your final value against the original FWA (8 inches). The answer must be less than 8 inches since the density difference is smaller than between full fresh and full salt.