"Innovative Diver" Communication Slates

[EliotD]

I saw this on Amazon the other day. I dont really want or need one, I am just curious if anyone has used one and if it works.

http://www.amazon.com/gp/product/B0002CSWD8/104-8303261-1918353?v=glance&n=3375251

 

[H2Andy]

my feeling is that anything that is not "i am ok" or "i am out of air" or "let's terminate dive now" is not imporant enough that it MUST be said. thus, it is best not said.

three signs: ok, out of air, terminate dive

that's all i need