Why you’ve limited yourself with those two types of greases? Anyway, for your type of application (under high water spray) the best choice would be grease with lower water washout characteristic. Some fully synthetic greases formulated from high viscosity base oil would be my choice for any underwater application, because they cling strongly to bearings (very tacky), and exhibit 0% water washout.
John is correct, better to choose a grease designed for use in wet conditions. For instance Mobilgrease XHP 222 is a Lithium Complex Grease but has tacky additives to prevent water washoff.
Hi tran, respected jhon may be right in low rpm and hi load applications synthetic tacky grease. the rpm & load factor can not be ignored. al clx.under waterwash conditions is better and ca clx. is good for submerged conditions.
Al clx has a better tackiness hence its good in humid condition but we see Ca sustaining the same thing water wash out of both these greases are of similar nature but not identical However we need to loook at the full application Some of the tackifiers are Cut back residual compound hence can be cercenogenic as well as source of enviornmental pollutants.
Hi For high water ingress / high water spray conditions, i would recommend Ca-sulponate grease and Li-Ca mixed soap grease in VG-460 or higher viscosity base oil. Later made in VG-460 grade containg acid funtionalised polymer (tackifier) found to perform extremly good in these stringent conditions. Bearing failure is reduced and regreasing interval also increased.