This paper presents an up-to-date analysis of the application of nuclear excavation technology to the design of a sea-level canal connecting the Atlantic and Pacific Oceans. This analysis is based on the technical data obtained to date under the auspices of the Atlantic-Pacific Interoceanic Canal Study Commission. Consideration is given in this paper to use of nuclear methods in the construction of a sea-level canal through the Darien region of Panama (Route 17) and the Atrato-Truando region of northwest Colombia (Route 25). The site data required for a comprehensive nuclear excavation design analysis of a proposed sea-level alignment include information pertaining to site topography, geology, hydrography, hydrology, meteorology, seismic propagation characteristics, bio-environmental conditions, and medico-ecology. These data are being used, together with data pertaining to nuclear explosive characteristics, cratering characteristics of pertinent geologic media, nuclear cratering detonation effects and channel design criteria, to develop an engineering-safety-cost analysis which is the basis for the nuclear excavation design. The results of geologic investigations to date along the 46-mile Route 17 alignment indicate that ∼20 miles of the alignment through the Chucunaque Valley encounters a weak saturated clay shale while the balance of the excavation would be through relatively competent rock. In view of the unfavorable long-term slope stability characteristics of these shales, techniques were developed for using nuclear explosives to produce linear craters that have initially flat slopes of the order of 7 to 9°. Experiments indicate that nuclear excavation using a two-pass, triple-row array detonation system may offer a solution to this problem. A preliminary analysis of the topography and geology along the Route 25 sea-level canal alignment through northwest Colombia indicates that conventional excavation techniques, primarily hydraulic dredging, would be the most reasonable method of excavating ∼78 miles of the 100-mile alignment. The remaining 23 miles of the alignment, through the Continental Divide, would be excavated using nuclear explosives. Studies in progress pertain to the safety aspects of using nuclear methods to construct a transisthmian sea-level canal, including consideration of seismic propagation, airblast acoustical wave phenomena, and radioactivity release. The results of such studies to date indicate that the potentially damaging effect on buildings from ground motions resulting from seismic propagations from the nuclear detonations will be the major factor in determining the maximum aggregate yield that can be detonated at any one time along the selected alignment.