FA-68985 / Tide and marine navigation tables / Member archive

Bridge air draft clearance: Transit margin is computed from the charted clearance · case 05

The displayed clearance is tide-corrected but the go decision is not.

Member previewVariant 5 · 3 implementations · 7 checks per implementation

Case contract

Input [c, mhws, tide, air, safety]: charted vertical clearance c is measured above MHWS; mhws and tide are heights above chart datum; air is the vessel air draft. Available clearance = c+(mhws-tide) (it shrinks when the tide exceeds MHWS). Return [round(avail,2), round(avail-air,2), avail-air>=safety].

Why this case matters

Tide tables and passage plans turn published predictions into go/no-go decisions about depth, clearance and timing.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
bridge air draft clearance [12.5, 6.1, 3.0, 14.9, 0.7]	`[15.6, -2.4, false]`	`[15.6, 0.7, false]`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.