This pictorial shows the SS Adriatic. I do not own this stamp yet. It is here courtesy of the Wikimedia Commons.
This stamp commemorates Columbus by showing a likeness of his flagship, the Santa Maria. Note: I do not own this stamp yet. It is here courtesy of the Wikimedia Commons.
This parcel post stamp shows a steamship and mail tender, presumably hauling parcels.
This stamp commemorates the 200th anniversary of the War of 1812 by showing the USS Constitution.
This pane of stamps shows ships and stagecoaches. It was issued for the 1997 Pacific International Stamp Exhibition.