A planning aid, not navigation or clearance#
FairlySoon helps you compare possible passages. It is not a chartplotter, a primary navigation system, an official weather briefing or an emergency service. A suggested departure, route line or favourable score does not mean that a passage is safe, navigable or suitable for your boat and crew.
The map cannot establish safe water#
Coastlines and place names are simplified geographic data, not hydrographic charts. A line that avoids the drawn coastline may still cross reefs, shoals, obstructions, restricted waters or unsafe approaches. FairlySoon does not establish depth, under-keel clearance, bridge clearance, buoyage, traffic separation or port-entry requirements.
Forecasts have limits#
Forecasts can be wrong, delayed, incomplete or too coarse to represent local conditions. Interpolation and compact data processing add approximations. Squalls, gusts, convection, coastal effects, steep seas and local tidal flows may differ substantially from what is displayed. Agreement between models is not a guarantee.
Check the time the forecast is valid for and pay attention to missing data or freshness warnings. Recalculate your passage with current forecasts close to departure. A blank layer, low lightning probability or absence of a warning is not an all-clear.
Rankings are comparisons, not safety thresholds#
Calculations depend on the forecast coverage, route-search limits, boat performance, comfort settings and motoring assumptions. They cannot account for every hazard, equipment fault, crew limitation or change at sea. Wind and currents drive movement; the comfort calculation also accounts for gustiness, waves, rain, CAPE and lightning probability where available. Pressure, cloud cover, temperatures and GMDSS warning bulletins do not directly affect route choice or comfort scores. See which forecasts affect routing and comfort for the full breakdown. Estimated duration, comfort and arrival time are not promises.
Warnings and lightning#
The GMDSS overlay is a secondary view of published marine bulletins. Coverage, parsing and updates may be incomplete. Read the original bulletin, check its issuing service and use official maritime safety broadcasts. Forecast lightning probability is not a live strike detector and cannot rule out a thunderstorm.
Before departure and underway#
Use current official marine forecasts and warnings, appropriate up-to-date nautical charts and publications, local tide and port information, and independent navigation equipment. Assess the vessel, crew, fuel, daylight, shelter and alternatives. Reassess conditions as they change and retain a plan if connectivity fails or FairlySoon stops working.
The decision remains yours#
The skipper remains responsible for the decision to depart and the conduct of the vessel. FairlySoon does not provide professional navigational advice or replace seamanship, a proper lookout or applicable maritime obligations. See the terms of use for service limitations.