How DO you catch these things?

CBH says !! after using Modest Lure. All my !! bites are sharks. Upping my perception with HQ Stuffed Peppers (P 3339, G3799 w/ peppers) seems to get me fewer Zogor Cores but still no Cloudsails.

I do Surface Slap the Zorgor Cores But that should not affect the Cloudsails, just my GPs.