History tells us that Taal’s volcano erupted 41 times since 1595. The Batangas towns of Tanauan, Lipa, Bauan and Taal have literally moved three or five times from their original locations due to the destructive boulders, sand, ash and mud laced with sulfuric acid unleashed by the volcano. Records also described how spectators from hundreds of kilometers away watched Taal volcano throw thunderbolts several kilometers into to the sky, while nearby residents were horrified seeing the destruction it rained upon their land. In 1754 the volcano is even said to have erupted continuously for 6 months.
Transformation:
Located on the lake’s southwestern shore is the 8.2 km-long
Pansipit was once wide and deep enough to welcome Spanish galleons – and saltwater flora and fauna. Over the centuries, the multiple volcanic eruptions eventually changed its dimensions transforming what was a bay into a lake. But even as the river narrowed and became shallower, migratory fishes continue to spawn in the lake where most of their fingerlings stay inside, adapting to the fresh water environment. Currently, jacks, snappers, turtles, banded sea snakes, tarpons, smelt, damsel fish, mullets and other species take up residence in the lake together with freshwater fishes endemic to the area. Famous among its fauna are the sardines (tawilis) and the jacks (maliputo). 
The Dive Site:
Of the lake’s 120 kilometers of shoreline, the most popular side is at Talisay, just below the 640m (2,100 ft) Tagaytay ridge. This section is accessible either from the ridge or through the Sambat Star Toll exit. The lake’s average depth is 60-65m and the deepest is 160m.
Although we have made previous dives beside the Volcano Island, this time we decided to dive along the mainland coast. Accustomed to the clear sea water, our new rockskipper team member, Bea L. Nakpil was quite hesitant in plunging into Taal’s fresh water. Intrigued by the book "The Mysteries of Taal" written by Prof. Thomas Hargrove, which describes the numerous dives and discoveries he made along Talisay and Balete, we chose a spot called Balas where the town of Tanauan was supposedly originally located before 1754. Hargrove wrote about finding the town’s submerged ruins along this shoreline.
We chose the Holiday Resort as our base, as well as our beach entry and exit points. The resort had a very minimal but comfortable facility which caters to activities such as camping, line fishing, sailing and trekking in the Volcano Island. The local people were surprised to see that we were actually going to dive in the lake. Although they knew of the sapao or rock formations present in the lake, they did not seem to know much of its origins.
Fresh Water Aquaria: Accustomed to clear waters, some of us were having second thoughts in diving in the lake with very limited visibility. Nevertheless, we proceeded with care, following our dive plan to the letter. Knowing the presence of lush, thick Vallisneria Spiralis and Hudrilla Verticilatas, we snorkeled over them and noticed that they were as tall as the depth where they grew.
After swimming a fifty meters out, we shifted using scuba and started our descent using our float line making sure that everyone was in touching distance and had a hold of our buddy line. We touched bottom at 6m (20 ft) where the lake grass was still present, but not as abundant and tall. After a minute of acclimatizing with the 1.2m (4 ft) visibility we followed our planned compass heading, until we reached a depth of 9m (30 ft). From there we turned left. Due to lack of penetrating sun rays, the vegetation ended at a depth of about 7.6m (25 ft). There were seemingly undisturbed piles of vacant unionaceans or elongated mollusks about 10cm (4”) in length covered with brownish algae. Spongillidae or white branching sponges sprouted at random. Gourami fishes 10-15 cm (4-6") in length thrived along the grassy borders, and were startled by our presence. These fishes are just one of the 52 species recorded.
The bottom sloped to about 45 degrees starting at depth of 7.6m (25 ft). We could not see beyond 4.6m (15 ft) further below due to the predominant brownish tint. After swimming for 50 minutes at 9m (30 ft) with still a lot of air in our cylinders, we decided to end our dive unfulfilled after not seeing any sign of the sapao.
Coral:
On a separate day, we made another dive in Balas. We swam in the opposite direction weaving the slope at 9-12m (30 to 40 ft). The water visibility was a little better, allowing a clearer view of the fishes and bottom substrate. Small empty corbicula manila clam like shells littered the bottom with larger clusters of spongillidaes. 
After
30mins we swam back and came across an unusual massive outcropping, like
uniformly stacked smoothened rocks (turtle shell shaped) about 30 by
20cm (12 x 8 inches) each covered with black brown algae type material.
Bea was ecstatic seeing the unusual formation. We decided to slightly
chip an inch-wide off the surface, and then noticed a white coloration
underneath. The texture was not of cement, but was quite brittle.
Although it didn't look like a well-carved wall, its 
We further surveyed the surrounding area to see the extent of this formation. We later marked it with our descent line, terminated our dive and took land fixes from our surface float to mark the spot. A Piece of History:
Dr. Hargrove mentioned in his book of old church walls in Taal made of hewn coral blocks. Recalling the white coloration and texture of the chipped rock we saw, we could say that our dives were productive. Although it would take an archeologist to confirm our speculation, we strongly feel that what we saw was a part of a ruin from an ash fall, and we are content to leave it at that for the time being. Who knows what else we might discover in the habitats of Taal Lake’s flora and fauna?
