Yeah - but they were there when I was a kid in the 70's and 80's so predates the notion of Estuary English. They come more from the fact Portsmouth had a big influx of dock workers from East end of London at one point. The vowels are completely different. Where london would take "town" and make it "taahn" (like a long ah sound) we say "teihn" (to rhyme with plane, but not pure, more breathy, hence my h) - it's not a pure. I would "oy" like in "boy". The vowels are very Hampshire.