Get the mosa to a agro u then swim to the barrier where he can't get u, get off Ur tame to mark where the barrier is and swim below the barrier 2 get him 2 agro u while u r shooting him and to stop him agro u swim above the barrier keep going above and below the barrier till its knocked out
JUST TAME A SQUID GRAB THE MOSA,DISMOUNT THE SQUID.....and put the Squid on passive I will no let go of the mosa.AND THEN THE SQUID WILL BE DOING TORPOR AND ALSO YOU CAN HARPOON IT OUT AND TAAAAAAAAAAMMMMMMMMMMMMMME!!!!
Ok, for those of us people who cant seem to get any pearls for a tuso to simply grab on a mosa and wait it out then i have a solution. Down in the depths there is a cave on the ragnorok map. Some call it pearl cave or mushroom cave. Either name works. What i did was i mad a crap load of tranq arrows, took a journeyman crossbow and a 227 meg (not neccessary. You can have any level an icthy works too) and lured a mosa into this cave. When you enter there is a fork in the path. Take a right and you will notice that the land comes up where your meg can get through but the mosa can't. Camp there with your crossboe and tranq it. Stand on land so you dont waste the scuba tank. Once it runs it should run into the wall that is opposite from the middle island. After its out grabs some narcotic and meat. I reccommend setting up a little FOB or mini base at the cave beforehand so you are prepared. Wait it out and enjoy your new underwater giga!