A major submarine slide occurred on April 27, 1975, in Kitimat Inlet in the Douglas Channel system on the west coast of Canada. Following this slide at least two water waves were observed, and it was estimated that the range (crest plus trough) of the first wave could have been 8.2 m. Two simple theories have been used here to estimate the wave height. By considering the uncertainties both in the observed data as well as in the calculated wave height, there is reasonable agreement.