Calculators
This page contains downloadable excel spreadsheets that do useful calculations.
Be careful - I built these for my own personal use. It is almost certain there are errors.  I would be interested in hearing about any errors found or other improvement suggestions.

Coastal Navigation Calculator - also includes some wave calculations

Electrical Calculator - battery bank & alternator sizing,  Voltage Drop Calculator, and related wire sizing calculator

Heat Calculator - insulation thickness and heater sizing

Hull structure calculator - for vessels that will encounter significant ice, based on formulas for ABS Polar class PS7 (Summer/autumn operation in thin first-year ice which may include old ice inclusions )

Hydraulic Calculator

Sailing Loads calculator

Vessel Calculator - the normal vessel ratios (such as sail area to displacement), some speed calculations and a prop pitch calculator

Winch Sizing Calculator

Wind Calculator - True and Apparent angles, Velocity made good & Tacking angle

Prototype:
Closest Point of Approach Calculator - This can be used when you are trying to avoid a tropical storm.  It's mathematically a more complex calculator than the others, and requires some user adjustments, so may not be as directly useful to others.  But it is a useful and interesting navigational concept to understand.

Links to other calculators

Engineering Calculators

Electrical Calculators

Sailing Calculators


The Wandering Albatross

Farewell, my friend! I give the luck and cheer;
Seafaring hearts fare always well at sea,
And love makes all things easy. Far or near
I wish thee good, when'er I think of thee;
May winds blow string for thee,
May waves roll long for thee,
The thunderous sea make chant and song for thee
Wherever thou may'st be.

Layard 1897