Regu penyelamat harus melawan naiknya permukaan air. Pemimpin operasi penyelamatan mengatakan bahwa tim yang terjebak perlu belajar menyelam atau menunggu berbulan-bulan hingga airnya mengering.<ref name="VOX-20180707">{{cite news |last1=Viswanathan |first1=Radhika |last2=Barclay |first2=Eliza |title=The 4 risky options to rescue the Thai boys trapped in a cave, explained - The boys may have to swim out of the cave, accompanied by a “buddy” expert diver. |url=https://www.vox.com/2018/7/7/17541602/thai-cave-rescue-boys-options-diving |date=7 July 2018 |work=[[Vox (website)|Vox]] |accessdate=7 July 2018 |deadurl=no |archiveurl=https://web.archive.org/web/20180707191151/https://www.vox.com/2018/7/7/17541602/thai-cave-rescue-boys-options-diving |archivedate=7 July 2018}}</ref><ref name = "bbc-months">{{Cite news |url= https://www.bbc.com/news/world-asia-44692813 |title=Thai boys 'could be in cave for months' |date= 3 July 2018 |work=[[BBC News]] |access-date= 3 July 2018 |language= en-GB |deadurl= no |archiveurl= https://web.archive.org/web/20180703021541/https://www.bbc.com/news/world-asia-44692813 |archivedate= 3 July 2018}}</ref><ref name=":1">{{Cite news |url= https://www.straitstimes.com/asia/se-asia/thai-cave-boys-to-get-4-months-food-diving-training |title=Thai cave rescue: 12 boys and coach to get 4 months' food, diving training |date=3 July 2018 |work= [[The Straits Times]] |access-date= 3 July 2018}}</ref> Normalnya, gua terendam saat [[musim hujan]] yang berlangsung hingga September atau Oktober.<ref name=":2">{{Cite news|url=https://www.bbc.com/news/world-asia-44720785|title=Thai cave rescuers in 'race against the rain'|date=5 July 2018|work=[[BBC News]]|access-date=5 July 2018|language=en-GB|deadurl=no|archiveurl=https://web.archive.org/web/20180705110815/https://www.bbc.com/news/world-asia-44720785|archivedate=5 July 2018}}</ref>
Survei menunjukkan sebagian gua terendam air. Tim pelajar terjebak {{convert|3.,2|km}}<ref name="TG-20180708-1143a">{{cite news |author=Staff |title=Thailand cave rescue: first two boys brought out – live - 11:43 am/et/usa|url=https://www.theguardian.com/world/live/2018/jul/08/thailand-cave-rescue-operation-divers-trapped-boys-live?page=with:block-5b422ae2e4b0cb7e6f6c3312#block-5b422ae2e4b0cb7e6f6c3312 |date=8 July 2018 |work=[[The Guardian]] |accessdate=8 July 2018 }}</ref> dari pintu gua dan {{convert|800|–|1000|m}} di bawah permukaan gunung.<ref name=":4" /> Beberapa bagian gua terendam dan beberapa bagian lain sangat sempit.<ref name=":3">{{Cite news|url=https://www.bbc.com/news/world-asia-44695232|title=How might the trapped Thai boys be rescued?|date=4 July 2018|work=[[BBC News]]|access-date=5 July 2018|language=en-GB}}</ref> Ada pula bagian gua yang arusnya kencang dan tanpa jarak pandang.<ref name="TG-20180702">{{cite news|url=https://www.theguardian.com/world/live/2018/jul/02/thailand-cave-rescue-divers-search-for-missing-football-team-live|title=Thailand cave rescue: medics reach boys|last=Reymenants|first=Ben|date=3 July 2018|work=[[The Guardian]]|accessdate=3 July 2018|archiveurl=https://web.archive.org/web/20180702230537/https://www.theguardian.com/world/live/2018/jul/02/thailand-cave-rescue-divers-search-for-missing-football-team-live|archivedate=2 July 2018|deadurl=no|type=live updates|df=}}</ref> Penyelam berpengalaman butuh waktu enam jam untuk masuk gua (melawan arus) dan lima jam keluar (mengikuti arus).<ref>{{Cite news|url=https://www.bbc.co.uk/news/world-asia-44747049|title=Thai boys 'can walk but can't dive yet'|date=6 July 2018|work=BBC News|access-date=6 July 2018|language=en-GB|deadurl=no|archiveurl=https://web.archive.org/web/20180706185748/https://www.bbc.co.uk/news/world-asia-44747049|archivedate=6 July 2018}}</ref><ref name=":1" /> Seseorang berpeluang meninggal apabila panik di tengah perjalanan.<ref>{{Cite news|url=https://www.independent.co.uk/news/uk/home-news/thailand-diving-dangers-thailand-cave-rescue-a8430006.html|title=Thailand cave rescue: Diving expert explains the dangers of trying to lead the children to safety?|work=The Independent|access-date=6 July 2018|language=en-GB|deadurl=no|archiveurl=https://web.archive.org/web/20180704083058/https://www.independent.co.uk/news/uk/home-news/thailand-diving-dangers-thailand-cave-rescue-a8430006.html|archivedate=4 July 2018}}</ref> Regu penyelamat mencari pintu gua alternatif untuk mempercepat perjalanan keluar.<ref>{{Cite web|url=https://www.washingtonpost.com/world/asia_pacific/us-uk-teams-join-thailands-search-for-13-missing-in-cave/2018/06/27/453594dc-7a82-11e8-ac4e-421ef7165923_story.html|title=Thai rescuers search for other entrances to flooded cave|publisher=''[[The Washington Post]]''|language=en|access-date=5 July 2018|deadurl=no|archiveurl=https://web.archive.org/web/20180705204041/https://www.washingtonpost.com/world/asia_pacific/us-uk-teams-join-thailands-search-for-13-missing-in-cave/2018/06/27/453594dc-7a82-11e8-ac4e-421ef7165923_story.html|archivedate=5 July 2018}}</ref> Bor digunakan untuk mengeringkan air dan sempat dipertimbangkan untuk membuka jalur keluar yang lebih mudah, tetapi lokasi pengeboran yang cocok tidak ditemukan.<ref name=":3" /><ref name=":4">{{Cite web|url=http://www.theguardian.com/world/2018/jul/05/rescuers-draining-thai-cave-in-hope-football-team-can-walk-out-before-rains|title=Thai cave rescue: army drains site in bid to free boys before monsoon|last=Safi|first=Michael|date=5 July 2018|website=the Guardian|language=en|access-date=5 July 2018|deadurl=no|archiveurl=https://web.archive.org/web/20180705145812/https://www.theguardian.com/world/2018/jul/05/rescuers-draining-thai-cave-in-hope-football-team-can-walk-out-before-rains|archivedate=5 July 2018}}</ref>
[[File:Water pumping near Tham Luang cave.jpg|thumb|Pompa dipakai untuk mengeringkan air dari gua dan danau hilir]]
Regu penyelamat memasang sistem pemompaan air dari gua dan mengalihkan arus air yang masuk. Berkat cuaca kemarau yang tidak lazim, {{convert|1.5|cm}} air dipompa per jam pada 5 Juli. Regu penyelamat bisa berjalan ke dalam gua sejauh {{convert|1.,5|km}}. Namun, hujan lebat diperkirakan turun tanggal 8 Juli sehingga berpotensi menghambat proses ini dan bahkan membanjiri tempat tim terjebak.<ref name="BBC-20180705">{{cite news |author=Staff |title=Thailand cave: Rescuers in race against weather as rains close in |url=https://www.bbc.com/news/world-asia-44720785 |date=5 July 2018 |work=[[BBC News]] |accessdate=5 July 2018 |deadurl=no |archiveurl=https://web.archive.org/web/20180705110815/https://www.bbc.com/news/world-asia-44720785 |archivedate=5 July 2018 }}</ref><ref name=":2" /><ref name=":4" /> Tanggal 4 Juli 2018, {{convert|1.600.000|l/hour|gal/hour|abbr=on}} telah dipompa ke luar gua.<ref>{{cite news|url=https://edition.cnn.com/2018/07/03/asia/thai-rescue-next-phase-intl/index.html|title=Thailand cave rescue: Search teams unsure how to free boys|first=Steve|last=George|first2=Kocha|last2=Olarn|work=CNN|accessdate=6 July 2018|deadurl=no|archiveurl=https://web.archive.org/web/20180705061904/https://edition.cnn.com/2018/07/03/asia/thai-rescue-next-phase-intl/index.html|archivedate=5 July 2018}}</ref> [[Republik Ceko]] menawarkan pompa canggih buatan dalam negeri; pemerintah Ceko memiliki empat pompa berkapasitas 400 liter per detik ({{convert|1.440.000|l/hour|gal/hour|abbr=on}}).<ref name=":6">{{cite web|url=http://www.visegradgroup.eu/news/babis-offers-help-in|title=The Visegrad Group: the Czech Republic, Hungary, Poland and Slovakia - Babis offers help in rescuing Thai boys from flooded cave|first=Webra International|last=Kft.|date=4 July 2018|website=www.visegradgroup.eu|accessdate=6 July 2018|deadurl=no|archiveurl=https://web.archive.org/web/20180707023028/http://www.visegradgroup.eu/news/babis-offers-help-in|archivedate=7 July 2018}}</ref>
Pada tanggal 6 Juli 2018, regu penyelamat menemukan bahwa kadar oksigen di dalam gua menurun. Mereka khawatir tim di gua berpotensi mengalami [[hipoksia (medis)|hipoksia]] apabila dibiarkan menunggu lebih lama.<ref>{{cite web|url=https://www.cnn.com/2018/07/06/health/thai-soccer-team-oxygen-bn/index.html|title=How a lack of oxygen is affecting the Thai soccer team |website=CNN |accessdate=6 July 2018 |date=6 July 2018 |last=Scutti |first=Susan}}</ref><ref name="The New York Times">{{cite web |last1=Ives |first1=Mike |last2=Paddock |first2=Richard C. |last3=Suhartono |first3=Muktita |title=Thai Cave Rescue Will Be a Murky and Desperate Ordeal, Divers Say |url=https://nytimes.com/2018/07/06/world/asia/thai-cave-rescue-divers.html |website=The New York Times |accessdate=8 July 2018 |language=en |date=6 July 2018 |deadurl=no |archiveurl=https://web.archive.org/web/20180707043109/https://www.nytimes.com/2018/07/06/world/asia/thai-cave-rescue-divers.html |archivedate=7 July 2018 }}</ref> Saluran pasokan udara kemudian dipasang di dalam gua.<ref>{{cite web|url=https://www.bbc.com/news/world-asia-44748924|title=Thailand cave rescue: Boys tell parents 'don't worry' in letters|date=7 July 2018|publisher=BBC|accessdate=7 July 2018|deadurl=no|archiveurl=https://web.archive.org/web/20180707104655/https://www.bbc.com/news/world-asia-44748924|archivedate=7 July 2018}}</ref> Pada 8 Juli, kadar oksigen turun menjadi 15%; kadar yang diperlukan bagi manusia untuk bertahan hidup antara 19,5% dan 23,5%.<ref>{{Cite news|url=https://edition.cnn.com/2018/07/06/health/thai-soccer-team-oxygen-bn/index.html|title=How a lack of oxygen is affecting the Thai soccer team|last=CNN|first=Susan Scutti,|work=CNN|access-date=8 July 2018|deadurl=no|archiveurl=https://web.archive.org/web/20180708084509/https://edition.cnn.com/2018/07/06/health/thai-soccer-team-oxygen-bn/index.html|archivedate=8 July 2018}}</ref>
