Well that was fun! I ran this 'for real' a couple of days after my initial route setting walk/run. I thought maybe I could sneak in under 3 hours - pushed a bit on the beginning uphill miles and was surprised to find myself well on course. Some of the downhill sections are an absolute blast (it was dry, which helps - parts of this route might be quite challenging in the wet). Let it flow towards the end and cruised in at 7 and a bit mins under - well pleased.
No real need for supplies on a route this short - I carried 3 x 500ml bottles* and some gels. A pint and a pasty at St Ives and life is good!
*there is a drinking water tap on the campsite at Trevalgan, you run right past it, I'm sure you'd get away with filling a bottle... but it's also only about 3 miles from the end.
Note: the watch says 15.94 miles, but I took the exact same route that 2 days prior came to 16.01 - go figure. Seems my watch logs things shorter the faster I go. Close enough though!