I spotted this on the marshes at Aldeburgh (Suffolk coast) on Thursday, 15 June. My guess is a Reed Warbler - and would appreciate some expert confirmation. Thanks.
Looks like a Sedge Warbler to me ;-)
(As always best wait for a 2nd opinion)
(Pardon the Scottish Accent)
I would go Sedge Warbler if that is a big creamy stripe over the eye and not just a photo artefact.
PS well done on mastering adding a photo, its not the easiest system to work out.