As the lads said it’s a little early,
but I gather your just looking for the best places around that will give you the best chance of getting a few early mackerel and I’m sure when they start showing you will be spoilt for choice,
One thing I found that will put the odds in your favour… I sat watching a gang of lads belting the leads out at Carrigaholt pier and catching very little for there efforts, just the one fish every now and then and me being the lazy git that I’ am didn’t fancy putting all this effort in for such little reward so I set up a float rod and plonked myself down with a flask of coffee and waited until the fish came to me,
After catching half a dozen or so using this method I looked around to see a few of the lads got the hint

and started fishing the same method,
The way I looked at it was the fish would come and go as they pleased so you could be slinging a lead till tibs eve and you might never connect with a fish but if your bait is in the water you can be sure the mackerel will find it,
A simple 2 dropper rig baited with anything you can get your hands on will work, I still do this anytime the fish are scarce… one time I only had worms so I broke them up and used them to catch a little flat fish for bait which in turn caught a mackerel that I used for bait to catch more mackerel then I used them to catch bigger fish Pollock / Conger and the like,
Try it next time you see that only the odd fish is being caught.
But dont tell anybody

ps. forgot to say one of them lads really bugged me in the end.. because he couldnt catch anything where he was fishing he came alongside of me and started to sling his float in front of me,
i had to stop fishing and stood looking into his face until he got the message and kindly moved slowly away.
Not only did he want to fish the way i did But he wanted to take my place too