blockade runners
They were actually called blockade runners.
Blockade runners.
The South used small, fast ships called blockade runners to outrun the longer Union warships and reach trading ports.
The north had the entire south blackaded by union warships so the south built small fast ships to get around them and export their supplies. However, they still couldn't much out soy they built an ironclad ship named the Virginia to estroy the blockade set by the North. They succeeded in destroying two union ships before the union destroyed the Virginia using a ironclad of their own.
Your teacher is probably referring to the "Convoy System" that was developed by the British Royal Navy & used by the Allies. It meant that merchant ships with the same cruising speeds traveled together in a group or "convoy". The group may be escorted by Navy warships that were capable of protecting the merchants from German U-boats, Q-ships, or surface raiders. Ships that were very slow, or fast would not travel in a convoy.
They didn't sneak by, they were just small and fast ships that could get away fast enough.
For all practical purposes, the Confederacy had no navy in the US Civil War. The South had built a small number of river gunboats to help protect Confederate interests on the interior waterways. They bought a number of sleek and fast cruisers from England. These ships made use of their speed to sink Union cargo vessels whenever possible.The Union's fleet was small when the war began. They quickly built warships and gunboats. The warships were successful to a measurable degree in blockading Southern trading ports. Their gunboat fleets assisted the Union's army in the interior waterways of the South.
The Union used ships to enforce a blockade on the ports of the south, so that they could not import war goods or export cash crops like cotton and tobacco. The Union also used ships to transport troops and as gunboats to bombard enemy cities and forts. Ships were very important to bring supplies to armies far from home. The most famous ships of the south were the blockade runners, small fast ships meant to take a few tons of cargo and sneak past the Union blockade.
The Confederate Secretary of the Navy was Stephen R. Mallory. He knew the South had no war fleet to take on the Union warships attempting to blockade Southern ports. With that said, Mallory's initial idea was a sound one. He envisioned small and fast Confederate warships to attack the Union's large cargo fleet. Doing damage in that sphere might force a number of Union blockaders to withdraw and defend the Union's cargo fleet. Later Mallory would produce more ways to thwart the Union blockade.
Monitor and Merrimack (vessel ships). Only fought once. Made of iron at the front. Ironclad ships were a new invention. These ships were covered with iron plates that would deflect shells. Tin-clad ships were river boats that were lightly protected by iron. "Blockade Runners" were a name applied to a varitey of fast ocean ships that were used to get through the Union blockade.
During the US Civil War, the Confederacy faced the economic problem of the Union's blockades. Trade was hampered but it did continue. Two major steps were taken by the South. One was to use torpedoes to wreck ships engaged in blockading ports and rivers. Additionally, the South had small but fast ships with large canons to destroy wooden Union ships. Many of these fast blockade breakers were ironclads which helped them survive enemy canon fire.
That would be our clipper ships, sailor!