After a little debate, an American Black Tern was confirmed Eccleston Mere in Lancs where it occassionally turned up at Prescot Reservoirs less than a mile away. This morning (1st Sept) the bird was relocated at Pennington Flash in Manchester along with a European juv Black Tern for good comparrison!
Check out http://www.birdingnorthwales.blogspot.com for comparison images between European and American Black Tern.
Also, staked it out for Willow Tit for nearly 40 minutes until on finally revealed itself. Also nice to see considering we don't really get them in North wales.