But here is the silver lining: cheap, affordable geotechnical drilling rigs are plentiful and price with performance. In this buyer's guide, you will learn important considerations in choosing the best geotechnical rigs for small contractors and cost-effective soil testing strategies.
[pdf] Depending on water depth and metocean conditions, geotechnical surveys may be conducted from a dedicated geotechnical drillship, a semi-submersible, a jackup rig, a large hovercraft or other means. [24] They are done at a series of specific locations, while the vessel maintains a constant position.
[pdf] A rotary drilling rig works by rotating a drill string, which applies downward pressure to a drill bit that grinds the earth. Drilling fluid or air is pumped down the drill string to cool the bit, carry cuttings to the surface, and stabilize the borehole.
[pdf] 
