Gauge Koblenz is on the Rhine at kilometre 591, on the km 566–592 stretch. The GlW is 77 cm and the fairway depth maintained below it (TuGlW) is 210 cm; after deducting 30 cm of safety margin the official rule of thumb comes out at Koblenz +103. In practice Koblenz +130 is used here, +27 cm against the official rule. At high water Marke I is at 470 cm and Marke II — above which the waterway closes — at 650 cm. This gauge has 3 forecast sources: the 4-day forecast from Elwis (green), the 2-day forecast from the Hochwasserzentrale Rheinland-Pfalz (red) and the 14-day forecast from the BAfG (yellow). Upstream lies Kaub, downstream Koblenz (Mosel).
Koblenz
It is often said (especially by a certain company that sells commercial depth charts and has an interest in this) that the official rule of thumb for Koblenz is only + 103 cm. However, this is only the case above the Moselle mouth where the Depth below GlW (TuGlW) is 210 cm; below the Moselle mouth it is 250 cm, resulting in an official rule of thumb there of + 143 cm (see Hinweis Fahrinne). However, people often sail with + 130 cm, but just as well with + 160 cm, it just depends on how much of a hurry you are in. There are no major bottlenecks like the Deutzer Platte, but rather very long shallow stretches where meeting other traffic can draw away just a little too much water if they don't adjust their speed a bit. See also the depth charts of the Dutch and German Rhine branches on pdf v20-08-2026.