Cave Trip to France & Spain
Our team has an annual cave diving trip to Southern Europe every year, this year we headed to Spain and France. In Spain, our target was Pozo Azul cave which is the longest single entrance underwater cave in the world.
We have not visited Pozo Azul before and our goal was to get to know the cave and dive through sumps 1 and 2. In no circumstances was this a easy dive. Sump 1 is 700m long and 20m deep, then you have 250m long dry chamber/water canal to cross before reaching sump 2. The second sump is the world’s longest sump, 5.1km long and it has a maximum depth of 70m. Our plan was to dive the sumps with double rebreathers and double scooter. Rebreathers used were ISC Megs, GG Flexs, and JJ-CCRs. The scooters were Dive Xtras Cudas equipped with lithium batteries, all capable of over 30km cruise range.
We used one day to setup the long dive with help of our support team, all of the rebreathers and scooters were placed at the start of sump 2, ready for us on the following day. After a good rest, we started the dive from the head pool, moving quickly through first sump with light gear. The 250M long water canal is a bit challenging due the flow. Once we arrived at the dry passage, we geared up. One rebreather on our backs and one sidemounted. One scooter was used to drive and we towed a scooter and a dry tube with a spare battery, sofnolime, and food inside.
A 5.1km sump really tests your scooter skills. If you drive in the wrong position, you pay for it with back pain. It’s extremely important to find a good equipment configuration and trim to be efficient. If you’re too slow, you accrue more decompression, and your reserves get low. If you’re too fast, you exhaust yourself and consume power too quickly.
The cave is very beautiful. Sump 1 has a high canyon-like shape and sump 2 is lower but has very detailed rock formations. Trigger time was about 2h before reaching the decompression. Roughly 4h of deco was needed to surface at Tipperary, the dry chamber beyond sump 2. There are really no flat dry areas in Tipperary, which makes it very challenging to camp there. Because of that, we ate and rested for two hours before heading back. The trip home took just as long as getting there and after 16h from first splashing in the water, we finally surfaced. What a trip!