The only Aqua Trailers I've heard of are in Oz, so I can't think they'll be of any help
I agree with the above - reckon they're a standard 1" taper roller hub on 4" PCD.
If you don't want to remove the hub and check the bearing numbers (L44643 cone and L44610 cup) then if you measure the PCD and it's 4" then reckon they'll be the ones.
more than welcome to text me a close up pic if you wish and I'll have a look for you (I say that to all the pretty ones..
To check - grab the wheel at two o'clock and ten o'clock (like a steering wheel) and give it a twist towards and away from you. There should be no discernable play. To grease them you'll need to take it apart and pack with grease.
All the best, Ben