New channel depth instructions enter into force on 15 November 2021

The Finnish Transport and Communications Agency Traficom has published the instructions ‘Principles and application of channel depths in Finland’. The new instructions explain how channel depths are indicated in the new N2000 nautical charts, and they strive to clarify the use of channels and the related responsibilities. The instructions, drafted in cooperation with the Finnish Transport Infrastructure Agency, will enter into force on 15 November 2021.

The new instructions replace the instructions The channel depth practice in Finland - principles and implementation (4955/1021/2011) issued in 2011. In addition to the current reference level for depth information based on the mean sea level in sea areas, the instructions observe the new reference level tied to the N2000 height system. The instructions must be applied regardless of the reference level in the nautical chart used.

“In the updated instructions, the term authorised draught is replaced by the term design draught. Fairways are always designed for vessels of a certain size, so-called design vessels," says Senior Inspector Stefan Engström from Traficom. “Design draught refers to the planned draught at which the channel’s design vessel can normally use the channel, but different draughts can be used in good conditions,” says Chief Adviser Olli Holm from the Finnish Transport Infrastructure Agency.

In future, detailed fairway data to be presented in nautical publications

The method of indicating channel depths in the new N2000 nautical charts is described in the new instructions. Design draughts for merchant shipping lanes (classes 1 and 2) will no longer be included in N2000 nautical charts. For these channels, the safe clearance depth is presented. Additional fairway data, including the design draught, will be presented in a separate nautical publication published by Traficom (sailing directions). The authorised draughts in current mean sea level (MSL) charts must be understood as design draughts in accordance with the new instructions.

“Even though the draught information on all channels is no longer presented on N2000 nautical charts, on the whole, the information published on channels will be more comprehensive and detailed in the future. Sailing directions can be used to provide seafarers with important information and instructions, which may be difficult to present in the standard format of the nautical chart,” Engström explains.

In the future, fairway cards published by the Finnish Transport Infrastructure Agency will also offer more design and other additional practical information related to channels for the purposes of navigation. The Finnish Transport Infrastructure Agency is initiating the process of replacing traditional fairway cards (for merchant shipping lanes) with a new digital service. Official Traficom sailing directions in compliance with the international SOLAS provisions will be linked to the fairway card service offered by the Finnish Transport Infrastructure Agency. 

More transparent presentation of responsibilities related to channels

The reformed instructions specify the use of channels and the related responsibilities. The instructions are based on the principle that the actual water level at the time of navigation is taken into consideration as an increase or reduction in the channel's indicated safe clearance depth and design draught. This principle is applied both for sea areas and inland waterways. The Channel Authority is in charge of safe clearance depths, and the channel user is responsible for the draught employed.

Stakeholders were requested to comment on the draft of the instructions in May. Traficom, the Finnish Transport Infrastructure Agency, the Finnish Meteorological Institute and the Finnish Environment Institute, as well as other maritime stakeholders, have collaborated on the N2000 fairway and nautical chart reform. The first N2000 nautical charts will be published before the end of the year.


Traficom: Stefan Engström, Senior Inspector,, tel. +358 29 534 6724, Twitter: @stefuEng

Finnish Transport Infrastructure Agency: Olli Holm, Chief Adviser on Waterways Management,, tel. +358 29 534 3338