well i have been researching a decent $100-200, 3-4in folder for a while so heres me 2 cents
for extreme wet carry and bashability i would look at either

benchmade griptilian or griptilian mini (not small just smaller) with 154cm plain edge blade
spyderco salt series, any number of sizes, in s30v or 154 cm plain edge

im a huge fan of benchmade axis lock opening design, spyderco uses a thumb hole that is also very good for ambidextrious opening, i just prefer the bm design

both of these knives have handles that are good when wet, and steel that is easily sharpened by a beginner, which you will need to learn to do and buy a setup to sharpen with (sharpmaker gets good reviews, i plan on getting one)

lots of other knives out there, handle a few in person and see what opening and lock design you find yourself liking, then pick good steel and a grip thats good when wet