A clogged drain by the coast usually builds up over the years. An older line has handled decades of sand, grease, and soap, and when one finally backs up, a small hand snake often isn't reaching the problem. Drain cleaning comes in tiers of equipment, and the right tier depends on where the problem sits.
It starts with a phone conversation before anyone's sent out. You'll be asked what's backing up, how often, and whether it's happened before. Those answers decide the equipment. A straightforward clog gets the standard machine, and a drain that keeps clogging gets longer equipment or a camera down the line, because a repeat clog usually means something in the line is worth seeing.
If what the camera finds is bigger than a clog, you'll get the explanation straight, plain English, and you say what happens next. Most of the time, though, the right equipment is all it takes, and the drain gets cleared.