Skills unfamiliar to Thai Navy Seals but key to the successful rescue of the 13 "Wild Boars" extracted from Tham Luang cave will be added to the training regimen of the Navy's elite unit to better prepare them for unexpected situations.

The 17 days spent in the treacherous cave complex in Chiang Rai's Mae Sai district not only tested the Seals' strength, but has prompted them to think about arming themselves with the skills needed to navigate flooded, dark and murky passageways.

"Seals need cave-diving training," Naval Special Warfare Command chief Rear Admiral Apakorn Yukongkaew said yesterday when asked to name a priority for his Seal unit after returning from the cave rescue mission.

The 127 present and former "Seals" -- a nickname given to those attached to the Underwater Demolition Team (UDT) -- handled the risks and pressure at Tham Luang well, but they still needed to be guided by world-renowned cave divers who also joined the rescue operations.

"Many simply did not know what to do," when they first saw conditions inside the cave, Lt Cdr Khai Tochaiphum, a former Seal instructor who also joined the rescue mission, recalled, adding that none had cave-diving experience. Yet the rescue went smoothly because it was so well-managed, he said.

Before the successful conclusion, the Seals and overseas rescuers were faced with decreasing oxygen levels and fears of further flooding triggered by downpours that have fallen on northern Thailand since last Wednesday. 

"We did better than expected. It's a victory," Royal Thai Fleet commander Adm Rangsarit Sattayanukun said as he welcomed the Seals and 32 Navy personnel at the Navy-owned U-Tapao airport in Rayong.

Adm Apakorn earlier on Wednesday met experts from SpaceX, the American aerospace firm, who donated a mini-submarine for use in the rescue mission. He offered it for use in the rescue but it was rejected.

"The Navy believes it could be helpful and practical in future rescue efforts and will conduct further testing in Bangkok in the near future," read a tweet from a user called Than R, quoting Adm Apakorn.

SpaceX founder Elon Musk tweeted back he was "glad to hear that".