Preparatory signal. Or, "Get prepared."
The Beginning... Or as we say in sailboat racing, "That's the prep signal." In racing, it means that there are four minutes to the start of your class. In this case, it will be substantially longer. That's because the first race (probably a race from Portugal to the Canaries and on to the Caribbean) will start in early November 2021 and finish about 30 or so days later. The hard part is that I don't have a boat yet. The harder part is that I have to build it first.