Plus the tugs that had been obtained to deliver the supplies to the fort had not shown up. The tugs had been delayed or prevented from proceeding by the same storm and rough seas that had delayed some of the larger ships of Lincoln's armada.
Although there were no tugs, the Pawnee had a boat that could carry in supplies. However, the heavy and rough seas were a problem for the Union ships that might provide cover for the Pawnee supply boat. The Baltic itself had already run aground in heavy swells on a shoal off the harbor and took time to get free.
From Maury Klein's excellent book, Days of Defiance"
Everyone [on the Union ships] had wanted to assist Sumter regardless of the batteries, but without pilots, buoys, or marks they dared not make the attempt.
Sumpter [sic] on the one side and the Fleet off the North Channel on the other, will effectively cover any relieving expedition, whether of open boats, tugs, or small vessels, from any maritime attack, and confine all resisting operations to the land batteries. Experience has shown -- as in the case of Gen. WILKINSON’S passage down the St. Lawrence during the last war [the Mexican War doesn’t count as a war in the Times view?], with five hundred boats, suffering but a trifling loss, in the face of strong shore batteries – that batteries cannot effectually prevent the passage of an armament. Still less can be done when the batteries themselves will be exposed to such a terrific fire as Major ANDERSON can for some hours at least, pour with his whole force on Moultrie and the battery near Cummings' Point, the only two places from which boats or light draft vessels can be fired upon to any purpose.But ANDERSON’S fire will not be the only one to which Moultrie may be exposed, as the smaller vessels can take with impunity positions from which shell may be thrown with great effect. No matter how brave or skillful the Southern troops may be, they will be under a fire which will render the entire stoppage of relief to Fort Sumpter [sic] nearly impossible.