PLANES OF REFERENCE
===================
 
On waters of Vuoksi Watercourse two planes of reference (datums) are used as follows:
(1) Low water (LW) is used for depth related information, e.g. soundings and 
    fairway depths, and heights of lights and other aids to navigation;
(2) High water (HW) is used for vertical clearences;
 
Both datums are based on water levels during sailing season and are equal to 
values NWnav and HWnav referred to in some publications. 
  
The heights LW and HW in different lake basins based on reference level N2000:
 
Lappeenranta to Savonlinna
   LW: N2000+75.40 m 
   HW: N2000+76.85 m
Savonlinna to Varkaus, Pilppa Canal and Joensuu
   LW: N2000+75.45 m 
   HW: N2000+76.95 m
Varkaus to Konnus Canal
   LW: N2000+81.53 m
   HW: N2000+81.63 m
Konnus Canal to Kuopio and
Kuopio to Ahkiolahti, Karjalankoski, Varistaipale and Karvio Canals
   LW: N2000+81.75 m
   HW: N2000+82.75 m
Ahkiolahti Canal to Nerkoo Canal
   LW: N2000+84.90 m
   HW: N2000+86.30 m
Nerkoo Canal to Saarikoski Canal
   LW: N2000+85.90 m
   HW: N2000+87.60 m
Saarikoski Canal to Kiuruvesi
   LW: N2000+88.80 m
   HW: N2000+90.70 m
Karjalankoski Canal to Juankoski 
   LW: N2000+88.40 m
   HW: N2000+89.05 m
Juankoski to Lastukoski
   LW: N2000+94.65 m
   HW: N2000+96.20 m
Lastukoski to Syvärinpää
   LW: N2000+95.90 m
   HW: N2000+97.15 m
Varistaipale Canal to Taivallahti Canal
   LW: N2000+95.87 m
   HW: N2000+96.02 m
Taivallahti Canal to Kaavi
   LW: N2000+100.85 m
   HW: N2000+101.45 m
Karvio Canal to Kerma Canal
   LW: N2000+79.90 m
   HW: N2000+80.85 m
Kerma Canal to Vihovuonne Canal
   LW: N2000+77.45 m
   HW: N2000+78.55 m
Vihovuonne Canal to Pilppa Canal
   LW: N2000+76.45 m
   HW: N2000+77.35 m
Joensuu to Utransaari
   LW: N2000+75.85 m
   HW: N2000+77.50 m
Utransaari to Lehmonsaari
   LW: N2000+75.90 m
   HW: N2000+77.50 m
Lehmonsaari to Kuurna Canal
   LW: N2000+75.90 m
   HW: N2000+78.95 m
Kuurna Canal to Jakokoski
   LW: N2000+84.20 m
   HW: N2000+84.55 m
Jakokoski to Kaltimo Canal
   LW: N2000+84.40 m
   HW: N2000+84.55 m
Kaltimo Canal to Uimaharju
   LW: N2000+93.40 m
   HW: N2000+94.55 m
Uimaharju to Nurmes
   LW: N2000+93.50 m
   HW: N2000+94.90 m
   
Finnish Transport and Communications Agency
Hydrographic Office 2025