The invention provides an image display system and method. The image display system comprises a position information obtaining device obtaining position information of a ship, an information storage device storing an electronic marine chart including seafloor shapes and a tide table, an image display device, an image providing device providing an image to the image display device, and a direction obtaining device obtaining the direction of the ship, wherein the image providing device obtains a depth below sea level at a position of the ship based on the position information of the ship obtained in the position information obtaining device, the tide table, and information related to depths indicated on the electronic marine chart, determines a visual field from the image display device based on position information of the image display device determined based on the position information of the ship obtained in the position information obtaining device, the direction obtained in the direction obtaining device, and a size of the image display device, creates a virtual space image of a seafloor shape below sea level at the depth within the visual field based on the determined visual field, the depth below sea level, and seafloor topography image data indicated on the electronic marine chart, and provides the virtual space image to the image display device, and wherein the image display device displays the virtual space image of the seafloor shape provided by the image providing device in a manner overlaid on a view from the image display device.