Research: Historical Dive Slates/Writing Methods?

[la-gamine]

I wasn't sure where to post this so please move this to the correct section if necessary.

I'm doing research for a novel I'm writing and one thing I need clarification on is how one would write underwater.

I've researched about dive slates but they all seem to be plastic, my novel is set in an 1800s like era so that wouldn't be practical.

I've had an odd tip that slate and chalk or pencil would work underwater, but I would like a real diver's opinion.

 

[j2s]

Pencil works under water.....The softer leads are best....The old divers would use slate, like the little slate boards they used in schools....They'd send messages to the surface by tying line to it and pulling it back and forth....'Need tools, more air, more hose', etc...They used chalk but a very hard compressed type that wouldn't dissolve so easily in water, but it would eventually.......When pencils and a material called melamine were invented they used that.....But by that time they had two-way 'top-to-bottom' communication systems in the hard hats.......Contact the Dept. of the Navy....They'll direct you to their historical site...There's always an 'old salt' that is a wealth of knowledge and loves to talk about things 'nautical'.......

 

[la-gamine]

Thank you so much for the detailed answer!