Swim at the Waterhead end of Lake Windermere. Parking is very close to the water edge so it’s easy to park up, don the wetsuit and wander across the road.
The best swim is to stick towards the west bank of the lake as the east side is busy with boats during the day, including the Lake steamers. Hugging the west bank is also good for beginners as you can stay relatively shallow and still go for some distance. Only spot to watch out for is the river mouth where the temperature drops a little.
There are plenty of other lake users at this point so it’s best to swim in the morning or evening and with a safety tow float.