Lovely place Watendlath, and stunning drive up to it. I fish it every year when up that way, although usually late May/early June. Is that a blue in the last photo? last year there were a lot of blues in there, they pull your string a bit

Fish are usually free rising, at least when it warms up, we usually catch plenty on suspender hare's ears, suspender hoppers and sedges, twitched if static not working. If bank fishing fish can be spooky and soon move out of casting range but just sit down, resist the temptation to keep re-casting, leave your dries out there and they will move back in, patrolling the marginally reed and lily beds. Hang on to your rod, takes can be quite savage! The fish switch on and off through the day as the wind/pressure changes, typical there, it seems to have its own microclimate thanks to the hills/valleys. Just have a cuppa when they go down and soon they will start rising again. Boat gives you more options though and you can pick fish up right across the middle of the tarn.
You can even come in for a nice tea and cakes at the tea shop and feed the friendly chaffinches, lovely place to spend a day

(....although I've also fished it when its been raining stair-rods, which is a bit more challenging!...still caught plenty tho, doesn't seem to put the fish off)