Hi Robert!
Welcome to steemit! Nice to meet runners here!
I see you are preparing your first marathon. I'm sure you will enjoy it.
Regarding the food/drink paragraph, as a marathoner I have to tell you that to eat something 1 hour before the race can spoil your run. :-) Try to eat mainly carbohydrates at least 3 hours before the marathon. The day before have generous lunch and dinner.
During the marathon bring any easy source of carbohydrates (gel) and salts and eat one every 7 km, drink every 5 kms but not so much, as you said "little sips"
Cheers!