Interesting paper about equator crossing rituals.
In meteorological science we can find explanations for the doldrums in this zone due to the pattern of atmospheric circulation, though it is perhaps not necessary to digest the entire complexity of scientific explanation. Fifteenth and sixteenth century sailors did not know all of the details of this, however, what mattered was that due to the wind system, doldrums were created around the equator which made the crossing of the line one of the rare moments of relaxation on board a sailing ship. On the equator, the doldrums were more frequent than elsewhere. Even causing trouble and fear, “the doldrums caused a reduction in the rate of work which could be filled with a rare possibility of an onboard party” (Rodrigues, 2005, p.214-215).
Aside for the lack of wind in the doldrums for Europeans crossing the equator meant losing sight of the North Star.