On a standard hydrovac job the truck parks within reach of its boom and the crew digs right beside it. Plenty of sites don't allow that. The dig point sits behind a building, inside a fenced yard, down an embankment, across a stream, in an underground parkade, or on ground too soft or too sensitive to drive a loaded truck onto. Remote and long-reach excavation solves the access problem by separating the truck from the dig.
Instead of moving the truck to the work, OE runs extended water and vacuum lines from the nearest safe truck position to the excavation point. The crew works the hose and nozzle at the dig site by hand while the truck — and all of its weight and footprint — stays clear. The method, the precision, and the non-destructive result are the same as any other hydrovac dig; only the reach changes.
The reason this is a real capability and not just "more hose" is the engineering behind it. Vacuum suction and water pressure both drop off over distance — every metre of hose and every bend adds friction loss. Reaching the dig point with enough suction to lift the slurry and enough pressure at the nozzle to cut the soil means sizing the hose and dig tubes to the distance, the elevation change, and the material being moved, then positioning the truck accordingly. Done right, the dig is productive at distance. Done by guesswork, it stalls.
Keeping the truck back is often a safety call as much as an access one. Parking a loaded hydrovac at the edge of an open excavation risks the edge failing under its weight; running the hose in from solid ground removes that risk entirely. The same goes for soft ground, slopes, and live work areas — the heavy equipment stays where it's stable, and only the hose goes where the work is.