'mostly' Herring Gull, a 2nd cycle (3cy). quite some smudges around head and neck, well patterned tail (1st pic), a bill which is suboptimal for cachinnans and well, the slightly darker grey upperparts can be found in either of the 3 pale grey taxa in 2nd and 3rd cycles, so nothing indicating a certain taxon. Hard to discern pattern in a swimming bird but alltogether I mostly see a Herring Gull here, possibly with a slight participation of cachinnans in it (odd bill shape, greyish median coverts).