At the end of the 17th century, a significant naval battle unfolded at the gates of Nojpeten, the capital of the last independent Maya kingdom located on the shores of Lake Petén Itzá. It was a battle between the Itza Maya and the invading Spanish forces, which ultimately sealed the fate of the former. The Itza Maya were known for their aggression and combativeness, which enabled them to resist the Spaniards for 172 years. However, they could not withstand the massive onslaught using firearms.

Although, unlike other regions associated with Maya settlements, no systematic research had been conducted here, local accounts indicated that artifacts from this great battle could be found in the lake.

The first expedition of Polish underwater archaeologists took place in 2018, and despite enormous logistical difficulties, expedition members managed to perform a series of 9999 dives. They made a remarkable discovery near the western shore of Nojpeten, believed to be the site of this historic confrontation. Among the findings were stone objects, resembling mace heads and likely from the Maya military arsenal, as well as complete ceramic vessels.

In 2021, a team of Polish underwater archaeologists supported by the Exploration Support Program embarked on a journey to Guatemala. Among the team members were an expert on Maya culture and a qualified technical diver. The expedition plan involved diving to identify areas with the highest potential and then conducting excavations.

Experiences from the previous expedition proved valuable when part of the equipment, including a compressor, was detained at the border, and only by a stroke of luck were the tanks filled thanks to the local fire brigade's generosity. This time, the compressor was sent much earlier and was already waiting on site.

After conducting initial dives, Hospital Island and the area north of Flores Island were chosen for further exploration, where a deposit and ritual vessels were discovered during the previous expedition.

The entire 2021 expedition was marked by very intensive diving. Many artifacts lay underwater, and the team spent entire days documenting their location and depth to preserve the archaeological context. The most interesting artifacts were extracted and immediately properly conserved.

One of the most intriguing and mysterious finds are three large flint chisels, found at a depth of about 17 meters in the company of vessels from various periods. It is unknown what their function was or from what period they originate. They could be ritual tools used in bloody ceremonies, or remnants of the 1697 battle.

The biggest surprise was the area east of the island. At depths from three meters near the reed belt to several meters, spectacular artifacts lay everywhere. During one of the dives, at a depth of five meters, the team stumbled upon something truly exceptional: a ceremonial vessel with the image of the Sun of the Night – Jaguar God of the Underworld. Using a specially built ejector, archaeologists very carefully extracted the artifact, which was then subjected to meticulous conservation.

Hospital Island also revealed its dark history. To the east of the island, team members found human remains, including four skulls. The Maya's penchant for bloody sacrifices is known, but despite analysis by Vera Tiesler, an expert in physical anthropology of the Maya lands, it was not unequivocally determined under what circumstances the victims ended up at the bottom of the lake.

The expedition turned out to be a spectacular success. The value and quantity of the artifacts extracted, as well as the vast amount of information gathered by archaeologists, greatly enhance the knowledge about this extraordinary lake and its history. The artifacts date back hundreds, sometimes even over a thousand years, and are evidence of the centuries-old cult of the lake itself, and most likely Chaak, the rain god.