A dive door and ladder assembly includes a door positioned on the side of a boat, preferably in a rearward or aft position. The dive door is attached to a horizontally oriented hinge on a bottom portion thereof, and opens by pivoting inwardly and downwardly (vertically). When the door is in an open position, the underside of the door is generally in a horizontal plane with the upper surface of the doorway, forming a platform for divers and snorkelers to stand on. The upper surface of the doorway further includes a small hatch that may be opened to reveal a compartment therebelow. A collapsible ladder may be positioned within the compartment, in a collapsed state, and may be pulled upwardly from the compartment and folded over the side of the boat, through the doorway and extended into the water.