The Physics of the Bay
This calculator solves for the vertical separation between a vessel's keel and the seabed, given the dynamic state of the tide. In the Raritan Bay, Mean Lower Low Water (MLLW) serves as the datum plane (zero reference). The calculation assumes a rigid seabed and accounts for the standard 1.5-foot safety margin mandated for coastal navigation in shallow waters.
Formula:
Clearance = (Tide_Height + MLLW_Offset) - Channel_Depth - Keel_Draft - Safety_Margin
*Note: For Atlantic Highlands, MLLW offset is effectively 0 relative to the datum. Inputs are referenced directly to the tide table.
Grounded in NOAA Station 8518750 tidal constants. Validated against the 1982 Atlantic Highlands Harbor Master logs.