Trailer bearing grease change

How often do you guys change grease in the trailer’s bearing?
I didn't change it for three years (bought it new with the boat and had no idea that it should be changed regularly) and then decided to take a look at what is inside and found some water in the grease and the bearing a bit rusted. Called the manufacturer then, asking about parts (to change the bearing) and was told that I should change grease - according to manufacturer manual instructions - every time after I put it into the water.
It’s not very complicated to change it - just open the rubber cap and put new grease through the valve with a grease gun (the old grease comes out). However it is still messy job and somehow expensive to change it every time if I go fishing some 10 times a year.
What is your opinion or practice on that?
Thanks!

I check mine in the fall. If there’s water, I replace and check the rear seals…

Get bearing buddies and don't worry about it anymore.... Couple shots of grease in the fittings before a long trip and that's it.

Bearing Buddies are great and keeping them topped up is easy but it is always a good idea to check the heat on them by a good 10-15 minute run down the road at highway speeds , if you can't put your hand on the bearing hub and leave it there because it's too hot you got a problem. Also too much grease is not a good thing as it too will overheat and probably blow a seal which you will see by the grease sprayed all over the rim. While the boat is off the trailer try jacking it up and rotating the wheels if you hear and grinding or growling you need to replace the bearings.

I clean out the old grease and repack mine every spring and inspect them at least once a month.
for the cost of grease and a new seal it gives you the piece of mind that you should be able to get home with zero worries. I've welded a hub assembly to an axel before and it's expensive and totally ruins a trip

Before I got bearing buddies I would do mine annually. With bearing buddies (or equivalent brand as you seem to have) just fill it until the spring has a bit of pressure and thats all you need to do. Make sure not to overfill otherwise it could possibly push the seal out the back of the hub which would let water in and destroy your bearings prematurely.

Thanks a lot, very helpful!
Yes, I now lift the trailer’s wheels from time to time and listen for noise . Right now I hear some sound only if I get my ear in touch with the metal part of the trailer near the wheel. Hope it is still OK.
But I never checked the heat of the bearing while traveling even though I normally stop during the trip after ½ hour or so to check everything.
Thanks for the suggestion!

I have bearing buddies on my trailer and i put in fresh grease in the spring and sometimes in the fall depending how much use.
like everyone said when you pump the grease in the old grease should flow out and stop pumping as soon as you see the new grease come out

Check yearly and service as soon as you see water. Or anytime before a big trip. Otherwise you end up being the guy who unhooks his rig on the side of the highway and goes to the nearest town for parts followed by a very dangerous repair on the side of a busy highway
Driveways are the place to work on these things.
And carry spare parts with you

I learned my lesson the hard way with my boat and trailer coming home on a roll back after a blown bearing. Now,I carry a bearing repair and tool kit just in case. I fill the bearing buddies once a season and check the rear hub for blown grease seals every few weeks.