🔍 Key Concepts

• Tide tables and tidal datums used for U.S. coastal waters • How sounding datum (chart datum) relates to mean lower low water (MLLW) and mean high water (MHW) • Finding Old Point Comfort data in official publications like NOAA tide tables or chart notes

💭 Think About

• Think about where you would normally find the elevation of mean high water relative to the chart sounding datum for a specific location like Old Point Comfort. • Consider whether this value is something you memorize, or something you would normally look up on a table, chart, or inset. • Ask yourself which of the choices best matches a reasonable vertical difference between chart datum and mean high water in that area of the U.S. East Coast.

✅ Before You Answer

• Make sure you understand that sounding datum on U.S. charts is typically referenced to Mean Lower Low Water (MLLW), and mean high water will be above that level. • Verify in a tide table or chart marginal note for Old Point Comfort what the stated height of MHW is above the chart datum. • Check that the value you pick is a plausible tidal range component for that region—not unrealistically small or large.