Originally Posted by Rogue Wave
that's not a problem but it's not much use without a chart or route plan
That depends on how far off shore you are venturing.
If you are doing coastal runs in an area you know well - a compass is still essential even with no charts - I have been caught in the dreaded Fog twice - I had no charts but without the compass, once you have lost sight of the land - that is it - FU**ED - your only chance if you have no compass is to stop the boat and hope to god you know which way the wind is blowing to get a rough direction from.
Lack of any visual reference will mean you have ZERO sense of direction - its even impossible to tell if you are driving in a straight line.
Any compass will do - and it doesn't need to be mounted to the boat - so unless the area you boat in has never ever been foggy (i assume there are places in the world where fog is impossible due to climate) never venture even a few hundred yards away from land because fog can reduce visibility down to an alarmingly short distance.