There has to be a seal either separate to or combined with the bearing. Without a workshop manual you will not be able to service this - it is critical to service this area of any jet system in the correct manner, if you get it wrong it might cost you a lot more than you think!
There are a lot of unique aspects to PWC - if you don't have a good manual and a pretty good idea of what you are doing then you will just cost yourself a lot of money, or even the ski itself - take it to a professional and then you even get warranty!
Good luck.
