Chiang Rai Gov. Narongsak Osotthanakorn, the head of the rescue efforts, said the equipment brought to help was not practical with their mission.
UPDATE- Elon Musk indicated that Chiang Rai Gov. Narongsak Osotthanakorn was not leading the rescue teams. Elon Musk was working with the co-leader who did ask for the mini-sub as an option for the smallest boy.
Two divers were assigned to each person to be rescued. Air tanks were pre-positioned along the route. After each batch of 4 or 5 people were taken out, air tanks along the route were replenished.
The mini-sub and rescue pods may end up being adapted as escape pods for space and the may get adapted as emergency equipment for over-turned cruise ships or ferries.