I worked for the largest pencil and oldest pencil manufacturer in the world for 10 years. I think I can tell you a little about pencils. First wooden pencils are made from three parts, the first being two slats of cedar wood, and grooved to hold a piece of graphite lead. The graphite and wood are glued together and pressure applied. Paint is coated on the out side, a ferrel and eraser if needed is fixed on one end. These pencils were never intended for use underwater. If used will swell, the glue will soften and the lead and (bonded) wood will seperate.
There is another type of pencil which used on paper is inferior, but works well under water. It's an extruded pencil. The wood and lead are both plastic and exturded at the same time. Since there isn't any wood, glue, or graphite to delaminate this pencil will not seperate. The best known brand of this type of pencil is American Pencil or Berol.
As for China Markers, or grease pencils, these will not work under water long as they are wrapped in paper with a string close to the wax core. The paper will soak and come off.
The best bet is to fine a cheap golf pencil made by American or Berol. Hope this helps. :doctor:
