Speculation
Dozens of theories have been proposed to explain the mystery, ranging from the mundane and plausible to the fantastic.
The most plausible theories are based on the barrels of alcohol. Briggs had never hauled such a dangerous cargo before and did not trust it. Nine leaking barrels would have caused a buildup of vapor in the hold. Historian Conrad Byers believed that Captain Briggs ordered the hold to be opened, resulting in a violent rush of fumes and then steam. Believing the ship was about to explode, Briggs ordered everyone into the lifeboat, in his haste, failing to properly secure the lifeboat to the ship with a strong towline. The wind picked up and blew the ship away from them. The occupants of the lifeboat either drowned or drifted out to sea to die of hunger, thirst and exposure.
A refinement of this theory was proposed in 2005 by German historian Eigel Wiese. At his suggestion, scientists at University College London created a crude reconstruction of the ship's hold to test the theory of the alcohol vapor's ignition. Using butane as the fuel and paper cubes as the barrels, the hold was sealed and the vapor ignited. The force of the explosion blew the hold doors open and shook the scale model, which was about the size of a coffin. Ethanol burns at a relatively low temperature with a flash point of 13°C or 55.4°F. A minimal spark is needed, for example from two metal objects rubbing together. None of the paper cubes were damaged, nor even left with scorch marks. This theory may explain the remaining cargo found intact and the fracture on the ship's rail, possibly by one of the hold doors. This burning in the hold would have been violent and perhaps enough to scare the crew into lowering the boat, but the flames would not have been hot enough to have left burn marks. A frayed rope trailing in the water behind the boat is suggested to be evidence that the crew remained attached to the ship hoping that the emergency would pass. The ship was abandoned while under full sail and a storm was recorded shortly after. It is possible that the rope to the lifeboat parted because of the force from the ship under full sail. A small boat in a storm would not have fared as well as the Mary Celeste.
Some people theorize that the alcohol was to blame, but for a different reason. They believe that the crew tried to break into the hold to drink the alcohol, murdered Captain Briggs in the process, and later stole a lifeboat.
Another theory has suggested there was a mutiny among the crew who murdered a tyrannical Briggs and his family, then escaped in the lifeboat. However, Briggs had no history to suggest he was the type of captain to provoke his crew to mutiny. First Mate Albert Richardson and the rest of the crew also had excellent reputations.
An alternate scenario has the ship encountering a waterspout, a tornado-like storm with a funnel cloud that occurs at sea. In such a case, it is suggested, the water surrounding the boat may, in being sucked upwards, have given the impression that the Mary Celeste was sinking. It would explain why the Mary Celeste was soaking wet when discovered by the crew of the Dei Gratia, and a mass panic amongst the crew during such an occasion would probably explain the scratched railing, and the broken compass found on the Mary Celeste, as well as the missing lifeboat. A further theory is that a seaquake panicked the crew into abandoning ship.
However, mariners generally agree that abandoning ship is an extreme measure.
Yet another theory supposes a case of ergotism derived from bread aboard the ship which could have led all its occupants to throw themselves overboard. However, the sailors from the Dei Gratia were not affected.
Brian Hicks and Stanley Spicer in recent books revived the entirely plausible theory that Captain Briggs opened the hold to ventilate it while becalmed. The release of noxious alcoholic fumes from the hold might have panicked the captain and crew into abandoning ship for the yawl, tied to the halyard by an inadequate rope. If this broke with a weather change and consequent wind it could easily have explained the sudden and mysterious exit from the ship.
One of the more popular theories at the time of the event was also that a sea monster or creature could have came on board and killed/taken the crew.
Another popular theory is that the Mary Celeste may have come across a mysterious island pushed up by an earthquake, and the crew and passengers went ashore to investigate – only for the island to disappear beneath the waves once more, taking them with it to their deaths
http://en.wikipedia.org/wiki/Mary_Celeste
