/u/The_Alaskan had an excellent comment about this a year ago. Link here.

The current academic consensus is that there is no consensus.

Let's review.

There have been four major investigations into the sinking of the Maine:
• The first took place in 1898, immediately after the sinking. The McKinley administration created a naval board of inquiry that concluded unanimously that the ship was sunk "only by the explosion of a mine situated under the bottom of the ship at about frame 18, and somewhat on the port side of the ship."

• The second investigation took place in 1911. President Taft ordered the Army Corps of Engineers to study the wreckage. Never to do anything by halves, the Corps built a cofferdam around the ship's wreckage, pumped out all the water and examined the exposed hull. Hundreds of photographs were taken, and the Corps removed much of the wreckage. A revised board of inquiry reaffirmed that a mine sank the ship, but it concluded the mine had detonated at a different place.

• The third investigation came in 1974, when Admiral Hyman Rickover, father of the nuclear Navy, asked historians to re-examine the case. The historians dredged Spanish archives and consulted with foreign militaries about their own experience with internal explosions. They consulted professional engineers to analyze the 1911 photographs and took into context the "natural tendency to look for reasons for the loss that did not reflect upon the Navy." This study resulted in How the Battleship Maine was Destroyed. That book concluded the explosion was, "without a doubt," internal.

• The fourth investigation came in 1999 and was conducted by the National Geographic Society. NGS commissioned a study by Advanced Marine Enterprises, which conducted the first detailed computer modeling of the disaster. AME stated that a coal fire within a bunker could have raised the temperature within one of the Maine's magazines to hazardous levels within a few hours. As to a mine strike, AME found that even a simple mine consisting of 100 pounds of black powder and a contact fuse could have sunk the ship. "If so, the mine must have been perfectly placed, which under the circumstances would have been as much a matter of luck as skill.” While it did not discount either option for the Maine's destruction, AME ultimately concluded (based on the 1911 photographs) that there was more evidence in favor of the Maine's destruction by a mine.

Let's review the competing evidence for each side, and you can make up your mind.

For a mine detonation:

• The Maine carried a type of bituminous coal that rarely spontaneously combusted.

• Bunker A16 was not situated by a boiler or any other external heat source, and spontaneous combustion does not occur unless there is a heat source to speed up the process.

• When Bunker A16 was inspected the morning of the disaster, the temperature was only 59 degrees Fahrenheit.

• The Maine's temperature sensor system did not indicate any dangerous rise in temperature on the morning of the last inspection.

• Discipline on the Maine was excellent, and regular inspections of coal bunkers for hazards, as well as the implementation of precautions for preventing bunker fires, were diligently carried out.

• A number of witnesses stated that they heard two distinct explosions several seconds apart. If anything else besides a mine had triggered the magazine explosion, then witnesses would have only heard one blast, because the only explosion would have been that of the magazines.

• The only reason that two explosions would have been heard is if something besides the magazine had exploded, such as a mine.

• Divers who examined the bottom plates of the Maine reported that they were bent inward. This was subsequently confirmed with 1911 photographs.

• Divers spotted a large hole on the floor of Havana harbor, something that would not have occurred with a magazine explosion. Those are directed upward, toward the path of least resistance.

For an internal explosion:

• Spontaneous combustion of coal was a fairly frequent problem on ships built after the American Civil War. Coal was exposed to air, oxidized and began burning. The heat was transferred to the ship's magazines, causing an explosion.

• The Maine's bituminous coal was more subject to spontaneous combustion than anthracite coal. Furthermore, higher moisture content increases the danger of spontaneous combustion. The Maine had spent most of the previous three months in Key West or nearby, where tropical moisture predominates.

• Bunker A16 had not been inspected since 8 a.m. The explosion occurred around 9:40 p.m. There was ample time (12 hours) for a coal bunker fire to smolder into a disaster.

• From 1894 to 1908, more than 20 coal bunker fires were reported on U.S. Navy ships.

• No one reported seeing a geyser of water thrown up during the explosion, a common sight when mines explode underwater.

• No one reported seeing any dead fish in the harbor and these would have been seen if there had been an external blast.

• Inward bending of the plates could have been caused by water displacement occurring at the same time the front of the ship was breaking away from the rear.

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At the moment most historians agree that it was an accident. There is at the very least no evidence that the destruction of the Maine was premeditated. One of the most important historians currently living who studies Cuba, specializing in the 1890s, was satisfied to simply cite the Rickover Investigation's conclusions (that it was an accident) and move on. http://www.jstor.org/stable/3640268?seq=3#page_scan_tab_contents

Some contemporary Americans certainly believed the Spanish had done it, as Perez points out in that same article. But we have yet to come up with any proof that Spaniards planted a mine (much less a good reason reason, since the last thing Spain wanted was US intervention in the war).

Some still push that it was a false flag operation by the US to enter the war. This was certainly the narrative of the post-1959 Cuban government. As of right now, however, this interpretation hasn't been able to present any proof. Interview with one such official can be found here: http://www.nytimes.com/1998/02/14/world/havana-journal-remember-maine-cubans-see-american-plot-continuing-this-day.html?pagewanted=all

As years go by and the rapprochement with the US becomes more real, Cuban politicians push this narrative less and less, or if they honestly believe it they keep it private.

Pushing the narrative that it was a premeditated by someone is more of a political position (a way to criticize the US, Spain, or whoever) than it is a tenable position among historians.