Fished Cullercoats loads of times over the years. Fish the tide up and down, couple of hours tops either side of high water, south breakwater only, never the north as said. Watch the sea as it will come over the south aswell at times so check the swell and tide heights.
It's very snaggy, use old tat as sinkers rather than leads, sparkplugs etc and expect to lose a fair whack of them. If you imagine a channel running straight out from the mouth of the breakwaters, thats where you want to chuck into. Catch results are variable, I've fished it day and night, had fish during the day but in fewer numbers. The fish are usually decent sized when they're caught there.
Safety of course, if you're going alone make sure someone knows you're gonna be fishing there and when to expect you back or ideally take a mobile and check in with a text every so often.