# What are the most common data fields of Inland AIS device?

It is mandatory that Inland AIS device to transmit up-to-date . Therefore, this page will give some hints for the boatmaster and explains (when applicable) for what reasons the data are used. For the daily operations, the boatmaster can also make use of the [checklist](https://ris.gitbook.io/ebrochure-iais/qr28).

| Data Field                      | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| ------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **User identity (MMSI number)** | The MMSI number is the identity number of the transmitting Inland AIS device and is assigned by the competent telecommunication administration and for on-board radio communication equipment. The assigned MMSI number is set by the specialized approved firm when installing the Inland AIS device. This number helps the authorities' vessel traffic management systems to identify a vessel and connect it to current voyage data.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| **Name of the vessel**          | The name of the vessel is set in the Inland AIS device by the specialized approved firm when installing it. The name of the vessel helps the boatmaster to identify traffic in the vicinity.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| **Vessel or convoy type**       | The *vessel or convoy type* is used by vessel traffic management systems of the authorities in order to identify the composition of a convoy and/or to plan lock cycles. Inland AIS provides a list of different vessel and convoy types to choose from. For a convoy, the convoy type may change for each vessel depending on the number and type of the coupled barges. For some vessels, the type may also change. This needs to be updated by the boatmaster for each voyage.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| **ENI number**                  | The ENI number is the Unique European vessel identification number. It is set by the specialized approved firm when installing the Inland AIS device. The ENI number is used by vessel traffic management systems of the authorities to identify vessels and connect them to their current voyage data.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| **Dimensions**                  | <p>The dimensions are the overall length and beam of the vessel or convoy. For a single vessel, those values are set by the specialized approved firm during installation of the Inland AIS device. For a convoy, the values must be set by the boatmaster according to the actual situation of the convoy. The boatmaster uses the dimensions of other vessels so as to ensure safe passing and overtaking.</p><p>The authorities use the dimensions in their vessel traffic management systems for lock planning and/or VTS services</p>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| **Position**                    | The position is used for displaying the vessel on a map. This position information of a vessel reflects the actual position of the Inland AIS device’s GPS antenna on board of the vessel. The position is used by other boatmasters and authorities.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| **Speed over ground**           | <p>The speed over ground is transmitted automatically by the Inland AIS device. The boatmaster uses the speed to identify if a vessel is moving and at what speed.</p><p>The vessel traffic management systems of authorities could use the speed over ground to identify if a vessel is moving. This allows to sort vessels which are underway from the one moored. .</p>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| **Course**                      | The course of the vessel is transmitted automatically by the Inland AIS device. It is used by the boatmaster and the authorities to determine the sailing direction of a vessel.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| **Navigational status**         | The navigational status gives an indication about the operation status of the vessel (e.g. ‘underway using engine’, ‘at anchor’, ‘moored’) and is set under the responsibility of the boatmaster ). The vessel traffic management systems of the authorities use this information for planning purposes. The navigational status might not be so important for the boatmaster, but to be informed that an Inland AIS device that is transmitting ‘Underway, using engine’ claims far more time-slots for transmitting in contrast to the navigational status ‘Moored’. In dense areas especially (such as ports) it helps to reduce the load to the system if the navigational status is set to ‘Moored’ when a vessel is moored. The navigational status is set by the boatmaster but some suppliers (especially Inland ECDIS manufacturers) offer the feature of an (semi)automatic setting of the navigational status based on the speed over ground. Howewer the boatmaster is responsible for the transmitted information. |
| **Reference point**             | The reference point of the vessel is in most cases the position of the AIS device’s GPS antenna. The reference point is set by the specialized approved firm during installation of the Inland AIS device. Only in the case of convoys does the reference point need to be changed, depending on the composition of a convoy. This is usually done in conjunction with the amendments of the dimension of the convoy. When the reference point is not set correctly, an offset of the actual position of the vessel might occur.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
