We’ve sailed at Rutland a number of times, although we’ve not used the trail. It looks pretty accurate to me. Rutland water is quite big, so the timings don’t look too bad for a swallow, particularly if you stop for ice cream!
We tend to launch at Whitwell rather than the sailing club. It was cheaper the first time we went (I haven’t checked since) and it has a pontoon alongside the slipway, meaning you can launch without getting wet feet. A very rare luxury in the East of England!