From: Toronto Canada
The common belief among naval officers in 1941 was that it would be very hard for aircraft to hit a ship at sea and maneuvering. The review of Billy Mitchell's successful sinking of captured German ships was not impressed at his hit rate on static ships and extrapolated that moving and maneuvering ships would be nearly impossible to hit. Almost no one in high command of the battleship navies kept an eye on development of aircraft, torpedoes and bombs into more effective weapons.
Similarly, the effectiveness of the Taranto raid by the British was largely considered to be because the Italian fleet was anchored and the Italians did not have good equipment for night time AA defence. The crippling torpedo hit on Bismarck was written off as a fluke. Fleet exercises with USN carriers would have shown that attacks on ships at sea were possible but there was little data to show a hit rate or hit effectiveness. Thus, the belief in 1941 that if the ships at PH could just get out of the harbour and get some "sea room" they would be much less vulnerable.
If that is true - and unforgivably some of the Admiralty thinking re the Far East suggests it was - then those Admirals were asleep during 1941 or simply not looking at what was going on in the Mediterranean.
The arrival of the Luftwaffe in the Mediterranean at the start of the year (Excess Convoy) and the withdrawal from Crete alone (not to mention Matapan) would have shown anyone even vaguely interested in naval air warfare, the damage that air attack could cause ships whether in port or not.
As indicated previously Pearl Harbor was attacked Feb 7 1932
Source is military.com but there are plenty of references / insights / studies in books with many and various opinions.
The USN "should have absolutely" understood the danger.
Judgement was clouded by cultural assumptions / Battleship devotees / "conventional wisdom" which is generally a euphemism for stupidity
Yarnell achieved total surprise. The airfields were put out of commission, with not a single plane getting airborne during the attack. The attacking force scored multiple hits, they dropped sacks of white flour to simulate bombs, on the battleships. The umpires declared that Yarnell's attack had been a complete success and declared him the winner. The Army and Navy brass, however, would have none of it. They complained that Yarnell had cheated. He had attacked at dawn on a Sunday morning, a time considered "inappropriate" for an attack. His attack vector from the north-northeast had mimicked planes arriving from the mainland. Most importantly, the Navy argued, low level precision bombing of battleships at anchor was unrealistic since "everyone knew that Asians lacked sufficient hand-eye coordination to engage in that kind of precision bombing."
Pressured by the War Department, the umpires reversed their decision and declared that the defenders had won the exercise. The Navy and its "battleship admirals" ignored Yarnell's contention that Pearl Harbor was vulnerable to an attack by naval air power. The exercise was widely reported in the press and was observed by Japanese naval officers at the Japanese consulate on Oahu. Some 10 years later, the Japanese Navy would launch an almost carbon copy attack on Pearl Harbor, utilizing six carriers and double the air power used by Yarnell.
A People that values its privileges above it's principles will soon loose both. Dwight D Eisenhower.