Through scale-model tests, the forces, moments, and the pressure distributions, including impact pressures, were determined for large diameter piers extending through large-amplitude wave system in which current strengths vary Tests were performed at 1/100 scale, simulating piers of the bridge for the Northumberland Strait Crossing, Canada These piers are partially cylindrical with a base diameter of 100 feet Close to the surface, where the wave action is greatest, they are conical Waves up to 25 feet and current up to 4 knots have been reproduced m the laboratory, according to Froude similitude The tests results fully support the known concept that, when the pier diameter is large in comparison with the wave length, mertial force becomes dominant Generally, the presence of current, either with or against the wave tram, results in a decreasing wave force Semiempirical relations were developed for force predictions that require the experimental determination of a singular coefficient.