Trailer wheel bearings - standard or stainless

For a trailer that gets dipped in seawater and freshwater is it better to fit standard spec wheel bearings or stainless steel bearings?

It's my understanding that standard will withstand more weight and wear less at least if they don't get wet, while stainless shouldn't rust if it does get wet. Would stainless be strong enough to take the weight of the boat? Do some wheel bearing greases cause stainless to rust or degrade?

My wheel bearings seem all good for now but I want to at least buy a spare bearing set and relube the existing bearings that are fitted. I contacted the trailer manufacturer who gave me the following information about what bearings etc my trailer uses...

PE1101 is the part number to the bearing kit ( see below )

BEARING KIT 1-1/16″[UFP STYLE]
Kit Includes:
Part Description QTY
PE1400 BEARING 1-1/16″ [44649] 2
PE1710 RACE 1″ OR 1-1/16″ [44610] 2
PE2015 1-1/16″SEAL [UFP] [198-138] 1
PH2012 COTTER PIN 1/8″X1-1/4″[UFP AXLE] 1

I've seen some of those components for sale in standard and in stainless.

my trailer uses the same bearing size. I have Timkens on mine....but I thought all bearings were SS. Regardless, I've been happy with my tandem and in brackish water.

Every bearing will rust "IF" water gets in.

Make sure that you only use good bearings. We had some cheap Chinese ones in our hubs and had one disintegrate on our way back from the coast. Luckily it was within 20 miles from home.

Remember “stainless” means stain-less but not rust proof…I have used standard bearings (not sure if they are stainless or not) and as long as you keep water out and grease once a year or so they last a long time. I have some spares in the garage now I’m curious to check with a magnet….

Lots of grades of SS some rust some don’t.

I never knew trailer bearings are available in SS. I’ve never pulled a rusty bearing out but I’m not on salt water.
I’m just greasing my old bearings because they seem too be ok and I’m afraid of the quality of new ones.

I just learned something, as my timkens are not SS. Seems most are not.