Required tug power and number of tugs needed in variable conditions of wind, current and waves isin most cases an assessment made by pilots based on their professional experience. However, assessments will raise questions by lawyers if something goes wrong. They will use tools to calculate what really is needed with respect to tug power and number of tugs. They have furthermore the advantage of time.
The Arctic magnetic pole does not move anymore. It runs, faster and faster. In recent years, even faster than expected. Therefore, geo-researchers have now had an unscheduled change to their world model and adjust their calculations, so that navigation with compass and other navigation aids such as a Pilot Plug, used by pilots around the world, continue to work.
