Sailors refer to the area where ships powered only by sails frequently get stuck as the (doldrums-trade winds-horse latitudes.) this area is at (90-0-60) degrees latitude.

Explanation:

only by sails frequently get stuck as the "doldrums."

The doldrums are an area where there is little to no prevailing wind (historically known because it obviously cannot fill sails).

The other BLANK should be the location of the doldrums in degrees from the equator: 5 degrees north to five degrees south of the equator.