Hydration for desert racing

Just regular water or Gatorade bottles with a straw. 

Drill a hole in top cap. Tape it so it doesn’t move away from the Bottom. Pit crew recoups after you went thru pit. 

it’s not science rockets

Yep and the main key to proper hydration is taking small sips. Small enough so that your body absorbs most of the water before it gets to your stomach. 

Taking gulps typically wont hydrate you nearly as good as taking small sips does.

Notjake, a friend of mine makes the product you are describing. This is what the guys use for SCORE Baja, National H&H, BITD:

https://hydrobuddykit.com/

Proper hydration starts a week or so before the anticipated event and not at the starting line. I've ridden a lot of ISDE Q's when I was younger (never had the $$$ to go) but had a lot of fun riding them. I would start hydrating well in advance and carried minimal water on my back. I would take a bigger drink at a check point since you can arrive early and wait for your minute.

Single use water bottle with a hole drilled in the cap, cheap clear hose from hardware store, some tape. 

Are you running out of water or ? 

I’ve always thought a second camelback and swapping it at the pit would be easiest but I rarely drink my whole 1.5L uswe 

Very cool. I didn’t know you could buy them pre made like that. 

Most of the GNCC guys run a small 1.5 liter or so pack with just water and usually the bottles they are getting are some kind of electrolyte mix especially in florida or a carb style drink or just a coca cola shaken up to make it flat.

Wait, you think that your body absorbs most of it's hydration/nutrition needs in the esophagus? 

Your body absorbs water in your intestines, after the stomach. Taking a ton of small sips or a large gulp doesn't matter assuming you're taking in the same amount of water

Punch a hole in the top of a water bottle and rig up some fuel line as a straw, tape it such that you can hold the bottle in your teeth without the fuel line pulling out of the lid. I always ran just water in the camelback and then some sort of carb/electrolite drink in the bottle during pit stops. If you rig it right, even after the pit stop is done you can ride down the hot pits with the fuel line in your teeth for a little more time to get something down. One tip that likely helped me the most staying hydrated in WORCS/Desert races with multiple loops is to choose a point or a few points on the track that you are going to take a sip every time. Ex: every time I hit this jump/turn/obstacle i'm taking a sip. 

Like Tim507 said, drink more the week before your event. If you are well-hydrated, you won't even need to drink all of what's in the USWE. On the other hand, if you are not well-hydrated, no amount of drinking while you are on the line will help. 

I rode an MTB Epic a year ago in Moab that was 27 miles + 5 back to the truck. I ended up dumping water at the end so I could lighten my pack. I had a 3L USWE pack and a standard bicycle water bottle. It's all about the preparation!

I totally agree with the physiology of hydration the week before and water absorption in the intestines.  The only caveat with small sips vs large gulps that I'll mention is I tend to get an upset stomach when I take several large gulps during high intensity workouts, ie a desert race. I do better with smaller sips as long as I stay on top of it.  I can also drink cool/cold water during races and several of my buddies say they tend to cramp a little with cold water so they stick to warm/room temp.