No, the speed of sound through water is essentially independent of frequency. Sound is a compression wave.
You're thinking of transverse, or surface waves: https://www.youtube.com/watch?v=95sQcSulRFM
Given the high amplitude and nearness to the gun I'd guess nonlinear propagation would play a big part so that's interesting. IDK if that makes for a more intense shock front.
Oh I know, I mean that the precedent of metadata scrubbing points toward url cleaning as well, imo.