Re: That really flat fish...
Yes cod can be caught in April/May - that's the best time for them. Once in a while I run across one while trying for bass that time of year. Got a 25' one two years ago in a few feet of water on a rubber swim shad on 10lb test - what fun!
They usually aren't in thick or very big but sometimes you get lucky. There are also red colored cod that live in the harbor area year round. If you get a red one that means it's a local. Keep an eye on the fishing reports they will tell you if they are around in numbers worth targeting them specifically.