If you dont have a vacume packer put youre fish in a ziplock bag fill it with water and get all the air out and most of the water. I always fillet my fish first but you will have to cut them up into managable size. To thaw: put them in the sink full of COLD water the faster they thaw the better as long as they dont get warm. I personaly think this is better than a vacume packer, but what do I know. this my tried and true method hope it helps.