A modular system, which may include a modular ramp for a landing craft, is described. For example, a ramp module according to some embodiments includes an enclosure defining a cavity, wherein the enclosure is configured to be removably received in a watertight recess formed in the hull of the landing craft. The ramp module also includes an extendible ramp operatively coupled to the enclosure and configured to be extended from the enclosure such that the ramp extends from the deck of the landing craft toward a shore to provide a support surface for unloading cargo onto or in close proximity to the shore. The extendible ramp is configured to be substantially fully retracted within the cavity, in some cases the enclosure forming an water tight seal with the recess in the hull and/or sealing the ramp, when retracted, in a water tight manner within its cavity.