nautical units

[anielsen001]

Are there units for nautical miles and knots? I didn't see any but wasn't sure if I should expect to find them in Unitful or in perhaps a module of their own.

They are straightforward to create and I would be willing to contribute if there were some suggestions about the best place to add them.

[sostock]

I don’t think these units exist right now in any of the unit packages. I’m not sure whether they should be included here or live in a package of their own.

[anielsen001]

Knots and nautical miles are standard for maritime and aircraft use and I think should be included somewhere convenient. These are two that I need all the time.

Others like fathoms and more obscure nautical units appear from time to time also, but probably would not be considered standard, and the actual definitions are not always consistently defined anyway.

[lukebemish]

With the various revised unit conversion factors that NIST is adopting in 2022 (as they're retiring the survey foot starting 2023), many of these less-commonly seen units will be a bit more standardized (in this case, especially fathoms and leagues, as they'll be based off of the (non-survey) foot). Unitful currently doesn't include most of these (when was the last time you tried to use furlongs, after all?), but I could see either including these in Unitful or making some sort of "UnitfulMisc.jl" or "UnitfulExtras.jl" package for all of the less-commonly-seen but still fairly standardized units.

I would be willing to implement either solution.