Preparing for a tournament is serious business, and I'm not talking about the physical and mental preparations. Packing the right gear and food is essential to making it all day; that is the point right, to win the finals? So let's start with what you can count on KOG for; in the grand scheme of things, it's not enough. Period.
We bring about 15 gallons of water and 10 gallons of Gatorade. We do not have a water source at the field to refill, so the hotter the day, the faster the water and Gatorade go. We do this as a courtesy to supplement what you bring.
Around lunchtime, we cook hotdogs for the players. Again, this will not sustain you all day, but it does help. You are burning a lot of calories out there, which is just like burning wood on a fire. If you don't keep feeding the fire, it goes out. If the player doesn't eat, they will succumb to fatigue and dehydration.
Below is a short list of topics that are worth a read. We run a lot of tournaments and we have learned a lot along the way.
Tournament food has a lot to do with preference, but the one thing that matters most is portion size. You are not going to want to eat a sub between your matches, plan on eating handfuls of food, frequently. Fruits, nuts, energy bars, and granola make excellent snacks that give you instant energy. At one point in the day, you may want a sandwich. Any lunch-meat, or other protein is advised. As for condiments, mayonnaise has an ill effect on a number of people; use caution with the mayo, especially in high heat scenarios.
Water, water, water - bring plenty of it. If you bring it by the liter or larger, it will be helpful to have a 20oz. plastic water bottle/tumbler to bring with you to the court when you play. Just as important as water, is salt, or Gatorade. Salt is what fires the water into your muscles and keeps you from cramping. Cramping is directly related to hydration. There are lots of home remedies for cramping, but I can only speak for one, that I know works. Always carry a jar of pickles in your cooler. It doesn't even matter if you don't like them. If you cramp, and you take a couple pulls of pickle juice, you will become an instant fan. I've seen people eat a pickle regularly throughout the day as preventative maintenance - it works. So remember, lots of water and a salt (sodium) source if you want to make it all day and remain healthy.
You have about 100 yard walk from the parking lot to the playing fields. A nice cooler with wheels and a long handle is dual purpose if you have a couple bungee cords or ratchet straps. If you have either of those, you can strap your shade tent, chair, and gear bag to the top of the cooler and wheel it along almost effortlessly. If you are a minimalist, soft coolers are light weight and will keep everything cold as long as you can keep it out of the sun.
There are not many sources of natural shade at our fields, so you are going to want to plan for some shade. A very common solution are the 10'x10' pop-up shade tents. While very common at our tournaments, real estate under them is scarce. If players do not own one, they usually coordinate ahead of time with someone that does. They start at approximately $70 and go up in price. If you are looking to find them at the best price, most places put them on sale at the end of the summer. If you purchase a shade tent, or already own one, wind can put an end to your tent. The stakes that come with most tents are useless; 6" needles as I call them. Do yourself a favor and go to Home Depot and get yourself a small hammer and 4 10" timber nails that will fit through the holes in the legs of the tent. A nice big washer for each nail will make easier to pull the nail out of the ground at the end of the day. There will also come a time when you and your partner are working a match. An umbrella is very useful during this time.
Chair or Blanket
When you are not playing or working, you are going to want to relax. Sitting on the ground with nothing between you and the grass gets old, fast.
It doesn't matter what kind of skin you have, melanoma does not discriminate. Make sure you get the kind that doesn't come off when you sweat.
A small well packed gear bag is essential. Make sure you bring any braces/supports that you normally play with. If you are a sweater, several changes of clothes and socks will keep you dry and comfortable. Bring a towel. You will use this more than you think. Make sure you and your partner have a ball to warm up with. KOG's outdoor ball of choice is the Spalding King of the Beach ball. Whomever brings the ball, should also have a pump in their bag.
A little extra cash might come in handy. On those hot days, we have a Good Humor Ice Cream truck that comes out to the tournament. He has snowballs, Italian ice, and of course, ice cream.