I was about 6th out of the pool (28 competitors) in my first attempt at a sprint triathlon in Lanzarote this year, but spent so long faffing around with my socks, shoes, helmet fastening etc (about 4 minutes, despite the fact that I was wearing a tri costume so had nothing to add or remove), that I was well down the field by the time I actually got myself on the bike. Fortunately, T2 was a lot smoother.
I’ve since been advised that there should be no real need for socks if you’re running 5k or less. I will definitely practice before I tackle the much bigger Eton Sprint in early summer.