Aberrant Swift at Walberswick

Photographing 2 species of Sea Slug and a very impressive looking Long Spined Scorpion Fish at NB's, Andrew & I quickly departed to pick up Rob W and Steve J. We arrived at Hoist Covert car park taking the only space left and walked /ran down to the reed bed. A crowd of people were looking west but dispersed as soon as we walked out, we had missed the bird, a Swift with a white- rump (a possible Pacific Swift) by just 5 minutes. Checking the Swifts flying around revealed nothing we walked west to the ridge. From here, we spotted up to 3 excellent Hobbies and a Bittern quickly flew up and settled in reeds just south of us, 500 yards away. A call from Carl B saying he'd just seen it and it was heading our way. Then James B picked it up in the distance but most of us didn't see it. The concensus of opinion amongst the lucky few had seen it was it had a white tail in addition to a large rump indicating it was an abberrant or partially albinistic Common Swift. walking back past the mill, we spotted Steve & Dot who'd just seen it, Rob W quickly picked it up and gave the best direction of the day when he said it flying left past 3 clouds together and I last I saw a Swift with white rump and white tail! Quite easy to see albeit at long range but nicely lit but the sun. A Hobby was also spotted south of the mill, flying around some dark cloud.