Explanation: Fully automatic GMDSS compliant battery chargers are designed to transition from a high charging rate to a lower, "float" charge rate to prevent overcharging. Overcharging lead-acid batteries causes the generation of hydrogen and oxygen gas (electrolytic gas) as the electrolyte begins to break down. This gas is highly flammable and explosive, posing a significant safety hazard in confined spaces like a ship's radio room. Additionally, this gassing leads to a loss of water from the electrolyte, which can damage the battery and reduce its capacity and lifespan. Therefore, interrupting the high charging process prevents dangerous gas buildup and preserves battery health, ensuring reliable operation as required by GMDSS regulations. While overheating (A) can occur during severe overcharging, and keeping the battery cool (D) is generally beneficial, the primary and most immediate safety concern addressed by interrupting high charging is the prevention of flammable gas generation (C). The electrolyte reaching 212 degrees F (B) is an extreme condition that would typically only occur after prolonged and severe overcharging, long after dangerous gassing has begun.