to get to the sevi islands you have to beat the rocket on one island.you mustgo close to them and then go up and talk to them and they will battle you after you beat the go inside and find the ruby and bring it to celio to get the sapphire you must go up to the dotted hole in six island and use cut to open the door and go to the top hole,left hole,right hole, and bottom hole.(go down the holes)then you battle the guy he'll take it and run to the rocket hideout on five island.
i've completed the game but thanks for trying to help..