Maritime Toolkit

Maritime Toolkit is ten small navigation and seamanship tools behind one search box. Type what you are trying to work out and go straight to it.

ANCHORING
Anchor scope from depth and bow height, measured from the roller rather than the waterline, which is where most scope calculations quietly go wrong. Swing circle from rode and boat length, with the reminder that two boats need the sum of their radii between their anchors, not between their hulls.

SAIL AND WEATHER
When to reef, weighted for the gust rather than the mean, because the gust is what puts the rail under.

LINES AND WARPS
Which fibre for which job and why, in one screen. Nylon where you want stretch, polyester where stretch costs you. Dock line diameter and the full set of lengths for a boat of a given size.

NAVIGATION
Compass deviation worked both ways, so you do not have to remember which direction the rhyme runs. Distance off by vertical sextant angle, with a warning about where the geometry stops being honest. Fuel range with a reserve policy applied, not just the theoretical maximum.

SAFETY
The man overboard sequence in order, written to be read now rather than then. Sound signals with what each pattern means and which rule it comes under, because one prolonged blast means different things in sight and in fog.

FOUR TOOLS FREE
Anchor scope, swing circle, when to reef, and rope for the job. The other six unlock together, once.

WORKS OFFLINE
No account, no signal.

These are working tools, not authorities. Sea state, your own boat and your own crew decide, and the official publications, the collision regulations, your almanac and your engine manual, always take priority.