Ok
There is two very quick ways to tell good grease for marine and trailers or any very good grease.
First is to put it between your fingers and see if it strings out,when you pull your fingers apart.
Thats a quick test but a very good one.The second is if you want to test a grease and you don't know what it is.But you want to use it.
Put a blob of grease about 1 inch by 1/2 inch thick on a plate of steel.Now hit it with a hammer.Hard.If it stays pretty much in the area.It's good too use on about anything.If bits of grease go in all directions,it is a very low grade grease.Not to be used in high stress/load conditions.
It's only a way to show the quality of grease,not it's intended purpose.There is many other factors that need to be looked at.
But if you are stuck,on the side of the road and need to get home.This may help.
Hope it does