This study originally planned the following steps:

 As the survey task progressed, a focus group meeting was held mainly due to the sparse return of the survey forms and the concern that the survey might not bring out the desired information. With dynamic exchange of information, ideas, and debate among the professionals knowledgeable about slow speed maneuvering, expert opinions could be collected in a relatively short time. Thus, after the results of survey were compiled for review and discussion, a focus group meeting was held to discuss and brainstorm results from a preliminary set of test maneuvers and performance indices.

　

3.1 Survey

　

 Many useful inputs and comments about slow speed maneuvers were gathered, nevertheless it was difficult to pin down the universally adopted maneuvers, test procedures and the indices, either by naval architects/math modelers or by mariners, for assessing slow speed maneuvering performance. Although the survey did not produce the information as hoped for, it did indicate that the formal assessment and reporting of slow-speed maneuvering performance is indeed an area that needs to be developed and established in the maritime community, It is also recognized that the criteria of slow speed maneuvering performance involves even more complicated issues. This pilot study only scratched the prerequisites for judging a vessel's slow speed performance.

　

3.2 Focus Group Meeting

　

 An information package was mailed to the participants before the meeting. The package included survey questionnaire responses and a collection of reference papers and documents to prepare them for the gathering. The meeting included a combination of presentation, discussion, and desktop computer demonstration. All was designed to obtain from the group of knowledgeable professionals a set of preliminary candidate maneuvers, their test procedures, and associated performance indices. The time for simulation demonstration, brainstorming session was insufficient, but many thoughts and rich information were gathered. Written comments on the preliminary candidate slow speed maneuvers were also received from several experts. Their comments, especially the extensive ones from Hensen [25], Norrbin [26], and Groh [27] have provided valuable inputs to formulate the modified suggestions found in Section 5 on slow speed maneuvers and their performance indices.

　

4.1 Speed Effects on Maneuvering Hydrodynamics

　

 In the Focus Group Meeting, Ankudinov, Jakobsen, and Mazurkiewicz [28] presented the hydrodynamic aspects of slow speed maneuvering in deep and shallow waters. They explained the governing mechanisms of slow speed ship hydrodynamic and presented the supporting test data. Key points include:

　

　

 Jakobsen, et al [29] also implemented an important effect of speed on resistance into simulation modeling to improve its accuracy: the increase in resistance coefficient with decreasing ship speed for low speed operation. The resulting increase in propeller loading can cause an increase in propeller wash and thus make the rudder relatively more effective.

　

4.2 Different Views of Judging Maneuverability

　

 Relatively speaking, engineers and mariners seem to collect, use, describe and exchange ship maneuverability information in different ways; they judge maneuverability from different perspectives.

　

　

4.3 Presenting Slow Speed Performance Information

　

 The slow speed performance information can continue to be presented in traditional tabulated format on paper. However, modern technologies should allow us to customize the information for different end users to serve them better in their own working context. Al-though this issue is far beyond the scope of this project, it is worthwhile to point out that

　

5.1 Selection Considerations

　

 The following considerations were weighed when formulating the suggested Basic and Additional set of Slow Speed Maneuvers:

　

　

5.2 Summary of Selected Maneuvers

　

Based on the requirements explained in Sec. 1.2, the gathered information and expert input described in Sec. 3 & 4, and the considerations above, eleven slow speed maneuvers are chosen as the basic set of slow speed maneuvering tests. They are

　

　

 For ships equipped with twin screws, two additional slow speed maneuvers starting DIW are suggested:

　

　

 For a ship equipped with bow/stern thruster(s), IMO has a general guideline on what performance should be tested or estimated. Eight additional maneuvers are suggested here based on the IMO guideline:

　

　

 The default test conditions for all these tests include: open deep and 1.2 depth/draft shallow water, calm weather, moderate uniform current, loaded and ballast draft. In designing the tests above, one could use other rudders and throttle commands. In most cases, there is no unique or obviously optimal way. A 35° rudder for turning and 20° rudder for overshoot test were adopted from conventional definitive tests. Other smaller rudder angles may be used for the complete investigation of maneuvering performance.

　

 The logic of choosing these basic and additional maneuvers was explained by Hwang in [33]. The test objective, conditions, procedure, and performance indices are described in the appendices of [33]. Note that the three Twist maneuvers in [33] have been combined into two tests in Table 3 for clarity. Table 2 and 3 summarize the purposes of the basic and additional sets of maneuvers.

　

 In order to facilitate the discussion in Sec. 6, the test procedure and performance indices for MER as well as the Back & Fill tests are included in the appendices of this paper. Note that these selections do not provide total information of slow speed maneuvering performance, but when they are tested systematically, they can provide quite comprehensive information, especially for math model validation and trouble shooting.