>>3576102It doesn't seem underexposed to me, it's a contrasty night scene, that's the best you can expect from handheld film shots in these conditions. Most of the sky and the sea is middlish grey, so your meter is fine.
An increase in contrast with the very fast films (Delta 3200, P3200) is expected too because 3200 is a slight push even if they were designed for it.
I guess the best results in terms of detail and tonality would be using a tripod, a slow film, and a slight pull in dev (or a compensating developer with minimal agitation).