Hold on one second! Not every grease is the same. Boat trailer grease is the wrong type to use because it is too thick. It is really designed for a marine environment. And it smells bad. If your bike regularly takes a dip in the water then you use that. Otherwise use something light like Phil Wood's grease which is designed for bicycles. If you don't believe me- try both types on grease on your pedal spindles and then spin the pedals. One will spin like molasses and the other will spin freely.
Now when it comes to something that don't spin- like your headset- boat trailer grease is perfectly acceptable. Likewise brake calipers, brake levers, etc.