RE: Water? lol..albertaoildude You are refering to diamond drillng with your comment. There are many types of drill rigs designs such as, ITH drill(in the hole, this would apply to a RC rig) and Top hammer,(a diamond drill fits this description) these two are the most common in both exploration and mining related activities.
A diamond drill rod has a core barrel and a hollow diamond studded bit to allow water to flow through, just as you explained.
A RC drill uses hollow rods with no core barrel as the cuttings are collected at the top or collar of the hole. Samples are scooped up or collected in a cuttings collector bag from which the samples are taken.
The RC bit style is very different from a diamond drill bit in that the bit is a threaded solid steel body type with carbide buttons or blades and is equiped with three small water holes drilled into the solid body for water to escape and effectively flush the hole of the cuttings.
Cheers...Mad