We're planning a 9 to 10 hour dive. We can't go that long without eating.
What kind of 'food' could replace at least 2 meals of the day so we can 'survive' a long dive like that?
We'll figure out if something can be eaten while scuba diving. But maybe someone has already done something like that or has another 'extreme' sport where normal food isn't applicable anymore.
I'm thinking astronaut food but where do you get that?
I'm looking for something that looks like tube of toothpaste or similar.
When I climbed Mount Everest in 2010 I went from 9 pm, when we started for the summit, until 5 pm the next day, without eating. I had only 1 liter of gatorade to drink in that time too. Obviously I didn't die, and it required a lot of energy, let me assure you. So you can 'survive' your dive, and I guess challenge your thought about 'we can't go that long without eating'. If you can drink during your dive then you can take in calories through sports drinks or gels. I imagine training for a long dive like that by progressively doing longer and longer dives without food but only with sports drinks might make it easier too. Hope that helps!
Update: just to add, I did not eat much before the ascent, as at altitude it gets hard to eat. Your body will not like it but it will survive. Getting past the mental barrier might be a bigger challenge.
That is extremely long dive that come with many potential problems. Hydration Nitrogen Build-up Hypothermia Nutrition Exhaustion
Hydration can be solved with soft bottles to drink from, camel backs might work well. Nutrition you could look at liquid meals; corn starch syrup, soup, meal replacement shakes which can then also be drunk while diving. Some people take soft food in small soft containers so you do not have issues with air space becoming compressed. also be wary of high sugar content foods and caffeine as these can assist in dehydration and also causing sugar spikes and crashes.
Most importantly first practice long dives with eating and drinking in a pool before doing it in the ocean and at depth.
Talk with technical divers who spend a lot of time at great depths and long hours decompressing as they will tell you what they experience.
If you're looking for liquid/squeezable food you have quite a lot of options.
Baby food in pre-made pouches. Surprisingly tasty, balanced meals and there's usually a range of texture options. Not cheap long term, but for a single dive each diver could easily carry enough to keep them well fuelled even if working hard.
Buy a DIY pouch prep machine. [a Infantino Squeeze Station](Infantino Fresh Squeezed Squeeze Station https://www.amazon.co.uk/dp/B009IWNPXK/ref=cm_sw_r_other_awd_UJqjxbPENBCM2) Designed for people who want to package their own baby food. You can make your own meals to taste, blend and package into squeeze pouches. You can buy disposable or reusable pouches.
A meal replacement powdered food such as a Huel or a Soylent.
As a diver myself I'm curious about how you're planning to ingest liquid/gel/soft food underwater. Do you have full face masks with a drinking function or are you just going to take a regulator out, swig from the pouch/bottle and then put the regulator back in?
If the latter then you should practice the procedure in shallow water and make sure you monitor the additional gas use from repeated purging as you drink a full bottle so you can factor it into your gas consumption calculations.
