VERDICT: TRUE The TikTok claim is substantively accurate. Every core assertion is confirmed by the peer-reviewed study and by the research team's own institutional announcement. Two minor phrasings ("in 2024" and "ran out of cable") are loose but don't change the substance. **Primary sources opened:** 1. Alcérreca-Huerta, J.C. et al. (2024), "Recent records of thermohaline profiles and water depth in the Taam ja' Blue Hole (Chetumal Bay, Mexico)", *Frontiers in Marine Science* 11:1387235 — https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2024.1387235/full 2. ECOSUR–CONAHCYT joint press release (29 April 2024), "Agujero azul de Taam ja' en la bahía de Chetumal, México, es el más profundo del mundo: Ecosur-Conahcyt" — https://www.ecosur.mx/agujero-azul-de-taam-ja-en-la-bahia-de-chetumal-mexico-es-el-mas-profundo-del-mundo-ecosur-conahcyt/ 3. Supporting primary source: Alcérreca-Huerta, J.C. et al. (2023), "First insights into an exceptionally deep blue hole in the Western Caribbean: The Taam ja' Blue Hole", *Frontiers in Marine Science* 10:1141160 — https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1141160/full **Claim-linked findings:** - **Location, name, and >420 m depth — CONFIRMED.** Taam Ja' sits in Chetumal Bay on the southeast coast of Mexico's Yucatán Peninsula. The 2023 paper states it was "now named Taam ja' Blue Hole (i.e., deep water in Mayan)." The 2024 paper reports CTD casts on December 6 and 13, 2023 recording 416.0 and 423.6 m below sea level and "conclusively verifies that the TJBH is now the deepest blue hole discovered to date, exhibiting water depths surpassing 420 mbsl, with its bottom yet to be reached." The ECOSUR–CONAHCYT release independently confirms the name ("Taam Ja' (agua profunda)"), the depth ("superan los 420 metros por debajo del nivel del mar"), and that the exact bottom depth is undetermined. - **Probe and "ran out of cable" — CONFIRMED in substance, with a timing nuance.** The scientists deployed a SWiFT CTD profiler on ~500 m of cable (the maximum the instrument supported) and did not reach the bottom; the paper notes the recorded depth was shorter than the 500 m cable because the instrument descended obliquely (~32–34° from vertical). So "ran out of cable before they ever reached the bottom" is a fair (if loose) description. One correction: the lowering happened in **December 2023**; the study was published in April 2024 — so "in 2024" refers to the announcement, not the fieldwork. - **Deep-water temperature/salinity resembling the Caribbean — CONFIRMED.** The 2024 paper compared TJBH waters against Caribbean Surface Water data (0–150 m depth at the Mesoamerican Barrier Reef) and coastal reef-lagoon data, finding "the CTD measurements hint potential yet undiscovered connections with the seawater of either the coastal reef lagoons or deeper coastal zones of the Mesoamerican Barrier Reef System," driven by "the notable increase of temperature (~ΔT>4.0 °C) and salinity (up to 37.5 PSU) at depths beyond 400 mbsl." The ECOSUR release states the deep water "se asemejaron a las que han sido reportadas en el mar Caribe a profundidades de 0-150 m, lo que sugiere la probable existencia de conexiones subterráneas entre la bahía de Chetumal y el mar Caribe." - **"That hints the hole is connected [to the Caribbean]" — CONFIRMED as a hypothesis.** Both primary sources explicitly frame this as a *hint/suggestion* of subterranean connections (the paper speaks of "potential yet undiscovered connections" and "the possibilities of forming part of an underwater intricate and potentially interconnected system of caves and tunnels"), not a confirmed fact — which matches the TikTok's "hints" wording. **Caveats (do not change the verdict):** the Caribbean link is a data-supported hypothesis, not proven; the fieldwork was Dec 2023 (published 2024); and "ran out of cable" is a simplification — the full ~500 m cable was deployed without reaching bottom, partly due to oblique descent.