I fish SF Bay and San Pablo Bay all the time and have found a couple things that really protect the boat and trailer:
1) Launch at a facility that has a washdown area, bring a hose and a Salt-a-Way mixture device to not only flush engines but washdown boat and trailer at end of day. I bring a brush on a pole to hit every part of the boat then rinse off with fresh water, boat, trailer, wheels, axles, etc.
2) The most important point: Mercury or Quicksilver corrosion guard. BEFORE launching in saltwater when everything is dry AND AFTER washing down and everything is dry, spray corrosion guard on every piece of exposed metal- wheels, bolts, winch, tongue and very important all latches and hardware in your boat, anything a key fits into, every hinge. It takes just a minute, wipe behind with a rag. I'm telling you 100% this keeps saltwater form ruining your boat. It literally dissolves corrosion and prevents new corrosion. I spray my chrome wheels that used to have a bunch of rust and the rust is gone and lug nuts/studs look like brand new. It's a game changer for exposed metal parts. Don't spray your anodes though! Those are supposed to corrode.
3) Do a quick detail of all fiberglass surfaces with Salt-a-Way and a towel. If it's sumertime and hot, rinse all carpeted surfaces with salt-a-way and then fresh water and let dry.
I don't have a "bass" boat but a multi-species, however it's all the same. You cannot run in saltwater and not take care of your boat. Salt-A-Way and Corrosion Guard are your boat's best friends.
Oh, and BTW, the motor is the least of your concerns. if you flush it, you are good. If concerned about that, ask over in the Mercury Motor forums you will be assured these motors can handle saltwater, you just need to flush properly, inspect things properly and add some anti-seize to your spark plug threads. (And Corrosion Guard to exposed metal parts - but not anodes)