Is it true that a diver's convulsion from CNS O2 Toxicity is always preceded by a warning sign?

The statement that a diver's convulsion from CNS oxygen toxicity is always preceded by a warning sign is not accurate. While many divers may experience certain symptoms such as visual disturbances, tinnitus, or sensations of pressure before a convulsion, these signs can be inconsistent and not present in every case. This means that relying on warning signs can lead to a false sense of security and increased risk. It is essential for divers to understand that convulsions can occur suddenly and without prior indication, making it crucial to adhere to safety protocols and be aware of the potential risks associated with high partial pressures of oxygen during diving. Thus, the correct understanding of the unpredictability of CNS oxygen toxicity is vital for maintaining safety in diving practices.