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Flagship Toolkit
Plan passage, clearance, fuel, tide, and encounter checks with focused marine tools.
Use these tools as planning support alongside charts, tide tables, vessel data, weather, and local navigation rules.
Before a coastal passage, a navigator can compare great-circle and rhumb-line distance, check the tide window, estimate fuel reserve, adjust ETA for current and wind, and review CPA/TCPA risk near traffic lanes.
| Tool | What it helps with | When to use it |
|---|---|---|
| Great Circle vs Rhumb Line Calculator | Compare great-circle and rhumb-line distance, bearing, and ETA. | Use when comparing route distance and bearing assumptions over longer passages. |
| Tide Window Planner | Estimate passable tidal windows around high tide for draft-limited transits. | Use when depth, bar crossing, marina access, or current timing matters. |
| Fuel Endurance + Reserve Calculator | Calculate endurance and range after applying reserve fuel policy. | Use before departure and when speed, sea state, or reserve policy changes. |
| ETA Current/Wind Compensation Calculator | Estimate ETA delay from current and wind speed penalties. | Use when current or wind affects speed made good and arrival time. |
| Under Keel Clearance Calculator | Assess UKC using depth, tide, squat, wave allowance, and safety margin. | Use when draft, tide, squat, or safety margin controls a transit. |
| CPA/TCPA Risk Calculator | Compute closest point of approach and time to CPA with risk banding. | Use when another vessel's track may create a close-quarters situation. |
| Anchor Scope & Holding Calculator | Check required scope and estimate holding confidence for anchoring setup. | Use it when this workflow needs a focused marine & navigation result. |
| COLREGs Encounter Classifier | Classify head-on, crossing, or overtaking geometry from bearing/course data. | Use it when this workflow needs a focused marine & navigation result. |
| Drift Estimator | Estimate set-and-drift impact on course over ground and offset. | Use it when this workflow needs a focused marine & navigation result. |
| Turning Circle / Advance / Transfer Estimator | Estimate turning radius, tactical diameter, advance, and transfer. | Use it when this workflow needs a focused marine & navigation result. |
Marine & Navigation
Compare great-circle and rhumb-line distance, bearing, and ETA.
Marine & Navigation
Estimate passable tidal windows around high tide for draft-limited transits.
Marine & Navigation
Calculate endurance and range after applying reserve fuel policy.
Marine & Navigation
Estimate ETA delay from current and wind speed penalties.
Marine & Navigation
Assess UKC using depth, tide, squat, wave allowance, and safety margin.
Marine & Navigation
Compute closest point of approach and time to CPA with risk banding.
Marine & Navigation
Check required scope and estimate holding confidence for anchoring setup.
Marine & Navigation
Classify head-on, crossing, or overtaking geometry from bearing/course data.
Marine & Navigation
Estimate set-and-drift impact on course over ground and offset.
Marine & Navigation
Estimate turning radius, tactical diameter, advance, and transfer.
It is planning support only. Use official charts, instruments, weather, tide sources, bridge procedures, and applicable navigation rules for live decisions.
Passage planning depends on several constraints at once; a route that looks fine by distance can fail on tide, clearance, reserve, or traffic risk.
Verify chart data, tide and current predictions, weather, vessel performance, local notices, and regulatory requirements.