Free tools
Free sailing and navigation tools
Interactive revision tools for boat anatomy, chart reading, tides, compass work, sextant basics, buoyage, docking lines, COLREGs games, signal flags, VHF range, and navigation calculations.
Fundamentals
8
Free tools
26
No login
26
Start sailing
A first step aboard: learn a little, try it out, and find what to practice next.
Start sailing
Before your first sail
Five short lessons to help you understand the boat, the wind and your role as new crew.
Start sailing
Crew knowledge check
Eight first-day situations with topic feedback and exact lessons to revisit.
Nautical fundamentals
Points of sail
Turn a sailing boat relative to the wind. Explore the no-go zone, reaching and running with guided examples and six practice questions.
Nautical fundamentals
Apparent wind
Explore true and apparent wind with adjustable heading, boat speed and wind speed. See the vectors, calculation, guided examples and free questions.
Compass Challenges
Daily no-login games with a safety-weighted score you can send to a friend.
Boat handling
Docking simulator
Daily Marina Mayhem challenge plus fenders, lines, wind, stream, prop walk, and slow alongside practice.
Compass Challenges
Who Gives Way?
Daily COLREGs encounters: choose the safest action, not only who has right of way.
Compass Challenges
Night Watch
Daily night-horizon lights: name the vessel, aspect and implication.
Learn the boat
Names, parts, flags, and visual recognition before the navigation work starts.
Boat handling
Alongside lines, springs, crew recovery, anchoring, and slow docking practice before the practical.
Boat handling
Docking simulator
Daily Marina Mayhem challenge plus fenders, lines, wind, stream, prop walk, and slow alongside practice.
Boat handling
Docking lines and springs
Rig bow, stern, springs and a breast line, then see how a spring lets you leave.
Boat handling
Man overboard drill
Shout, throw, point and mark, then recover a fender dummy from leeward.
Boat handling
Laying an anchor
Pick a drop, pay the right scope, and see whether a fictional cove holds or drags.
Read the water
Chart datum, tide motion, tidal heights, buoyage, and marks.
Nautical fundamentals
Chart datum
Understand chart datum, charted depth, drying height, height of tide, depth of water, bridge clearance, springs, and neaps.
Nautical fundamentals
Tides in motion
Explore how Moon phase, spring and neap range, a local harbour tide curve, and the rule of twelfths fit together without treating them as one clock.
Navigation marks
IALA Region A buoyage quiz
Practice Region A lateral marks, plus cardinal, isolated danger, safe water, and special marks.
Tides
Tidal heights practice
Read a tidal curve and estimate height of tide between high and low water.
Navigate
Chart symbols, compass references, vectors, and celestial-navigation foundations.
Nautical fundamentals
Chart reader
Use a fictional nautical chart to practice symbols, soundings, hazards and route choice, then learn how to measure distance with dividers and the latitude scale.
Nautical fundamentals
Compass workbench
Practice true, magnetic, and compass bearings with variation, deviation, hand-bearing lines, and a simple chart fix.
Nautical fundamentals
Sextant simulator
See how a sextant doubles angles, align the Sun with the horizon, and work a simplified noon-sight latitude calculation.
Navigation maths
Distance, speed and time
Calculate any of the three navigation quantities, see the working, and complete six practice problems.
Chartwork
Estimated position workbench
Combine course, speed, time, leeway and tide in a visible DR-to-EP vector plot.
Navigation
Course to steer practice
Apply tidal vectors, leeway, and heading corrections in navigation problems.
Rules and radio
Recognition and communication practice for COLREGs and VHF revision.
COLREGs
Lights and shapes
Practice vessel lights, day shapes, sectors, and recognition drills.
Marine radio
Radio simulator
Practice VHF call structure and radio procedure in a guided simulator.
Marine radio
VHF range calculator
Estimate the geometric radio horizon between two aerials and learn why real coverage varies.
COLREGs
Boat sound signals
Hear and practice manoeuvring, warning, restricted-visibility, anchor, and aground signals.