Salt is bad enough. Add in INDUSTRIAL chemical dumping. Like Paper Mills or battery recyclers ? Eat metals alive quickly.
A large sewage plant can dump some large amounts at night. Why are my underwater metal parts so PITTED ? Then add in dangerous 120 vac leakage currents from power...
I have found a decent CLEAR filter does wonders to prevent erratic problems. Caught a watery load of gas. And a few bits of black rubber hose.
Changed the squeeze bulb as soon as it started taking a EXTRA squeeze to get hard.
Have you checked ALL / each sparkplug to see if some are different ? Like the start of a head gasket starting to leak ? Been there and hated the random problem.
I remember the NEW LIGHTWEIGHT H2O being praised by Chaparral. My 2002 SS 186 weighs 3800 # Very difficult to get it leaning with 200 pound people.
Do post # 13. Or add rock bags under some seats.
You might be very sorry when a electronic system has a problem.
Points only 2 parts to change and adjust. Buy a few spare hold down screws if you drop small parts.
Get a outboard motor if you want to trim the drive up. When in shallow water. They do not have those troublesome U Joints. My Mercruiser 2002 never had a inspection or problem with drive joints