The role of computer based simulation is increasing on the ships bridge, especially for manoeuvre planning and for collision avoidance.

 The development goes from current Path prediction based on Curved headline to more comprehensive methods.

 In the NACOS system from STN is a tool for calculating the ships track on the basis of integration of current motion parameters as "curved headlines" (see Figure 7).

　

　

 In the Radar system there is a module for calculating the expected ships track as "trial manoeuvre" for elementary course change manoeuvres at way points, using simplified equations (close to the approach used for automatic track control system to follow this predicted track). While these tools are dedicated to one simple course change manoeuvre only, new approaches are under development (starting e.g. with [13][14]) which are trying a series of manoeuvres to reach the final destination based on more sophisticated models. One example is presented in Figure 8 where a search method is used to bring the ship into a harbour basin by generating sequences of elementary manoeuvres which are checked and selected with respect to their efficiency to contribute to reach the objective.

　

　

 Each of the manoeuvre sequence element along the predicted paths displays a ship symbol at each position, when a new elementary manoeuvre is started.

 In this example the manoeuvre plan generated consists of five elementary manoeuvres and leads to an approach of I 0.0 m to the target position specified.

　

2.4 Design of Simulation Scenarios, Control of exercises and evaluation of results

　

2.4.1 Scenario design and compiling exercise scripts

 The scenario design should be capable in such a way as to create all situation elements in a comfortable manner which the trainee must be confronted with in order to prove his competence and to achieve an adequate standard of training i.e. by reacting with sufficient skill and according to the quality standards. Aspect of these design process are:

2.4.2 Exercise run with online assessment and surveillance

 During the exercise run the instructor has to start and to control the exercise, to act as several communication partners simultaneously and perhaps to steer other target vessels as well. Sophisticated tools support his job in up to date simulators:

　

 He must synchronize checking the trainee's progress by observing their actions and taking notes and/or filling in checklists about occurrences during the student's performance so that all advice and remarks, which cannot be seen in the record files for replay alone, can be given afterwards.

 The surveillance tool will then trigger alerting messages according to the configuration. Each message is displayed as status information on the bottom right hand corner of the instructor's monitor display; alternatively an entire list of the alerting messages can be displayed at one time.

 Finally, each violation of an adjusted limit value will produce a marker, which indicates the event when the exercise is replayed. This helps the instructor to quickly find an important position that should be urgently discussed with the trainees.

　

2.4.3 Debriefing and off-line assessment

 In the debriefing session the instructor assesses the results of the trainees by using the replay to discuss the results and additionally referring to his notes and checklists. Several forms of replays are:

　

 For these detailed evaluations the design of scenarios becomes more and more important because the objectives to be met in the exercises have to be clearly defined by parameters and the threshold for the assessing the students' results and level of compliance right from the beginning. Problems might occur in very complex exercises where many part tasks have to be managed and where the students have more than one option to react. In those cases the evaluation script will also need to be parted into exercise sections with a separate protocol for every section. In this way even for scripts with several branches the evaluation script can handle the complex structure of the results. The final protocol will add each single evaluation scores for the segments together and gives an overview over the complete exercise.