The 4th Casili Spring Exploration 2012

Posted: March 29, 2012 in Cebu Explorations

The 4th Casili Spring Exploration was conducted last March 28, 2012.

Using better equipment this time, Doc and Bernil navigated through the 48cm/1.57ft opening of the MAD Gate and down to the Snake Crawl with relative ease in comparison to the previous dives. The Hollis SMS 100 system and the helmet mounted lights worked very well as expected.


The objective of the 1st dive on this trip was to reach a maximum depth of 50 meters. 50% and 100% oxygen bottles were brought specifically for the purpose of the expected decompression requirement that obligates one to complete when diving to such depth.

Due to the  previous rains that have swept Cebu over a span of days, the water was heavily silted and our lights resulted in heavy back scatter giving the dive an impression of driving through a very foggy road on a very dark night (pretty much like a night time drive through Cebu’s foggy Transcentral Highway).

Taking additional precautions due to the limited visibility in a confined space of the Mantaga Sanctum resulted in a loss of time and the dive was turned after 25 minutes, max. depth was only 20.3 meters. The total dive time was 44 minutes with a depth average of 12.3 meters.

Through the Gate

Through the Gate

The emerging routine of entering the Casili underwater cave:  On sidemounts, swim down to Mad Gate with both bottom clips off, go through Mad Gate  in 2 units – the pair of 11-tanks in front, totally unclipped, followed by the diver. Continue on the same configuration through Jean Marc’s Trap, a 19-inch squarish restriction past Mad Gate, down Snake’s Crawl then re-don the gear and establish proper streamlined hoses-and-everything routing.

What about staged and deco tanks? Probably the best way to do is set them in place before the dive. The fastest time that we, a 2-man team, has established down to the bottom of Snake’s Crawl is about 20 minutes, an average of 10 minutes per diver (Bern, I stand corrected on this). No doubt, the time will improve as we do this routine over and over again.” – Doc Amores ]

While feasting on the famous Liempo for lunch, the 2nd dive’s objective was agreed upon. The left side wall of the cave was to be explored, and the chamber to be lined.

After a 2 hour surface interval, the 2nd dive proceeded. Reaching the end of Snake Crawl, a jump line for the chamber exploration was tied off from the main line (the one that leads to 30 meters). Neutrally buoyant, staying close to the ceiling and maintaining the wall on our left side, the expansive chamber was carefully explored with a guide reel. Average depth was 12.2 meters.

The chamber walls brought us back to our starting point at a depth of 16.5 meters. The line was then tied off at the side of the wall. The added line will guide us on succeeding trips for the continuing exploration of the magnificent Casili Spring.

4th Casili Exploration Diagram

4th Casili Spring Exploration Diagram

Additional Notes:

The recent rainy days created a stronger than usual water flow on the river bed. The turbulent current resulted in the “softening” of the river’s gravel bottom giving us a challenging situation when the truck’s rear wheels got stuck 500 meters from the site. Yes, we know– a 4WD system would be better.

Luckily, a 10-wheeler dump truck came by; with a borrowed rope that was used as a water buffalo’s leash plus a handful of men and kids, we managed to extricate the Strada from its predicament and onto a safe spot on the riverside.

The “portering” of 9 units of 80cu/11 liter tanks (weighing 16 kilos each), 3 units of 5.5 liters tanks, a case of regulators and a host of other equipment from and back to the truck was not a joyful affair. Nevertheless, that is all a part of an explorer’s life.

  1. Xavier says:

    How long its the cave already?

    • bernil says:

      we’ve laid a line to a depth of 32 meters but the tunnel still continues further– we hope to be back there this coming Thursday to extend the line up to 50 meters deep if possible. Will update you soon. cheers!

  2. Lee Black says:

    i know what costume i’m going to wear for halloween this year!

  3. Club Vera says:

    Great post. Disappointing you didn’t make your planned depth on the 1st dive, but sounds like you still managed to extend your knowledge of the cave. Will you be producing a revised map?

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