Flip flops and t-shirts are the usual garb. Mind you, a couple of days ago 2 idiots walked out to a spot called 'the island' off Fleetwood - it is a mussel crusted bank that appears at low tide. Unfortunately for them, the tides have been high and they started out as the tide turned and started coming in. They quickly found that whilst they were had reached the 'high' spot, the tide had passed either side of them and they were then cut off on a shrinking plot that was 3 metres lower than the high water mark. The lifeboat got to them as the sea reached their chins.
( Apparently, according to the lifeboat coxswain, people who are used to holidaying in the Med, which is just about tide-less, are currently taking 'staycations' and are confused when the sea recedes and then comes back in ).