I haven't tried all of the neptunium weapons yet but the bow, with the same enchantments as my regular bow, doesn't appear to do the same damage. I have Power V, Infinity on both. With my minecraft bow, it takes only one shot to kill a squid but takes 2 with the neptunium bow. Doesn't matter if I am in or out of water.

We are running 1.21.1
Neoforge 21.1.203
Aquaculture 2 Version 2.7.14