Thread: Map and compass techniques

Originally Posted by LBD

Okay ...Okarito... if I recall my history, there was at one time a degree of shipping of timber from Okarito ....back in the day.

And there was a similar practice in Havelock (Marlborough Sounds).... Ships would sail out from the mother country where they had loaded the holds with Ballast rocks... now the greater the density of rock, the less volume required, the lower the centre of gravity and the greater the ships GV moment or righting force.

The ballast of choice was a high iron content rock which was also very magnetic.... I cannot say for certain that is the case in Okarito... but out from Havelock there is a local magnetic anomaly is a result of piles of such ballast.

Interesting, this is an area inland from the coast tho.

Also would this not have made navigation on said ships rather difficult?