"Marine" grease = "boat trailer" grease.
Slightly bluish-grey in colour, this is a lithium-based grease that is highly water resistant (making it difficult to wash off your hands - it's usually easier to wear gloves than wash up later.)
Many "marine" greases are EP-rated now, but check your cannister to be sure. It's also worth noting that many "moly-based" chassis greases are more water-resistant than they used to be, and nearly any "moly" grease is going to be EP.
Extreme Pressure greases are required for the "load-bearing" ball joints in front suspension (in our case, the one on the lower control arm) and are highly recommended for universal joints and serviceable wheel bearings. Lithium greases are not typically rated for high temperatures, and that should be borne in mind when bearings to be serviced are at wheels with disc brakes - although lithium greases work well with drum brake bearings (discs get quite a lot hotter. Ever seen a brak disc glowing bright red?)
I've been using Sta-Lube EP Moly (red) for quite some time now, with no trouble. Granted, I don't play in water much, but I also grease quarterly. If you spend a lot of time in water, it's a good idea to relube everything after your trip anyhow - no matter what you use, water will find a way in, and greasing everything will help to flush that out. You could probably go either way - but if I played in the water more, I'd switch to an EP lithium.
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