Speed from sat nav against log

[l'escargot]

Are these calculations still valid for a planing hulled boat?

Yes, in good conditions - provided your paddle wheel/transducer is fitted where it gets a constant flow of water without turbulence etc. If it's rough and you're jumping or pounding waves there will be variations in log readings and revs, even your GPS will be averaging the speed.

 

[superheat6k]

If you want to get really silly, then factor in that the train doing 30mph is on the rotating surface of the Earth, itself flying through space at a couple of million mph. Where does that leave you?

Er, Clapham Junction ?

 

[Quest]

If you want to get really silly, then factor in that the train doing 30mph is on the rotating surface of the Earth, itself flying through space at a couple of million mph. Where does that leave you?

A long way from home?

 

[taz]

If you want to get really silly, then factor in that the train doing 30mph is on the rotating surface of the Earth, itself flying through space at a couple of million mph. Where does that leave you?

Bloomin dizzy?