Oldham Aquatics is more of an advanced training scheme. Swimmers expected to go 4, 5 or 6 times a week depending upon the level they're at. Oldham Seals have three sessions a week and is fairly popular. I think ORCA, based at Royton, have more sessions but I'm not certain as they have recently got a new coach. Seals beat Orca by just four points in the last gala between them so I would say its much of a muchness. You could also consider Chadderton or Saddleworth