Most shooters I know, are using 1/32 - 1/24 - 1/16oz jigheads, for dock shooting. Myself, I use 1/16oz in most cases. I will go to 1/32oz, if I find the fish suspending shallow under the dock ... but, usually only if there's not much wind to contend with.
I don't worry too much about the "splash" factor ... it get's their attention
But, seriously ... I've shot jigs into the sides, undersides, posts, and other portions of a dock, several times over --- then get a jig to go where I want it to, and still catch fish. If they can tolerate all that noise and commotion, a little splash ain't gonna send 'um scurrying off :p
... cp