Instructions and Examples 
33 
Conversion to different levels 
The predicted heights of high and low water refer to 
the chart datum at the reference stations. Heights 
above chart datum are considered positive, heights 
below chart datum negative. To obtain the actual 
water depth, the predicted height of the tide should 
be added to the charted depth taking into account 
its sign (see graph on page 9*). It does not matter 
whether a German or foreign nautical chart is used. 
The following example shows how the height of the 
tide is referred to a level other than chart datum. 
If the explanatory notes (or Information about depths 
in green) on a nautical chart covering the German 
North Sea coast Include the remark that depths are 
referred to Mean Low Water Springs, 50 cm has to 
be subtracted from the heights Indicated in the Tide 
Tables. The available water depth Is computed by 
adding this reduced height of the tide to the charted 
depth. 
Example 2: 
What is the time and height of morning low water at Bremerhaven on 7 June 2015? LW height is to be referred to mean low 
water springs (MLWS). 
No. 
Place 
LW time 
Prediction 
Part I, page 46 
103 
Bremerhaven 
10 26 
LW height 
0.5 m 
Tidal Constants 
Part III, Table 1, page 202 
103 
Bremerhaven 
MLWS 
0.46 m 
The LW predictions are referred to Chart Datum (see graph on page 9*). 
Proceed as follows to refer it to mean low water springs (MLWS): 
0.5m - 0.46m = 0.04m 
The LW height (NWH) thus obtained is rounded to full decimetres: 
0.04 m 0.0 m 
Result: 
Bremerhaven LW time 10 26 (UTC + 1 h 00min) LW height 0.0m (MLWS)