Examinations are made of the dynamic effects associated with modal res
ponses of deep-water, wave-excited offshore structures. Such examinati
ons are intended to assess the influences that variations in several p
arameters involved have on the dynamic structural response. Variations
in the following parameters are considered: the distributions of the
structural volume and projected area, the distributions of the inertia
and drag force coefficients, the relative magnitude of the inertia an
d drag force components, the natural modes of vibration of the structu
re, and the random phase angles used for the generation of the wave lo
ading. The response is examined for a wide range of values of the natu
ral frequencies of the system, and the relative importance of the effe
cts of changes in the parameters considered is elucidated. The results
of the study provide valuable insight into the response of offshore s
tructures to wave forces, and may contribute to forming a basis for th
e development of future, efficient design procedures in the field of o
ffshore engineering.