Shirley-- This list of ships at Pearl Harbor comes from the official US Navy website on their FAQ page.One would think it is comprehensive and, considering the source, complete.However it does not list any of the several PT (Patrol Torpedo) Boats which were at Pearl that day, one of which lays claim to being the first US vessel to shoot down one of the attackers.(And for the benefit of your search, a PT had the most firepower per tonnnage of any combat vessel in the Navy) As a place to start, you might notice on the list that there WAS a PG-19 (Patrol Gunboat)SACRAMENTO on station that day. I have visited Pearl Harbor on several occasions, and have met many survivors of the attack.There are any number of reasons why a crew may have been ordered not to fire.One that comes to mind--only as a possibility-- is that the ship was in some condition that would have been terminal had it invited a retaliatory attack--refueling, ammunition transfer etc. I met a veteran and survivor of the attack once who was aboard the USS PYRO which was an ammo ship.Needless to say he characterized his situation as being in absolutely the wrong place at the wrong time.He also said that if his ship had been hit, Pearl Harbor would have had another cove! It is possible that whatever ship your Uncle was on may have been near enough to some other vessel or shore installation that, had it fired on the attackers and invited return fire, the collateral damage to the ship and surrounding area may have been devastating. BTW--Navy people have a very definite distinction between what is a BOAT and what is a SHIP.Basically, a BOAT is any craft that can be lifted out of the water and placed on the deck of a larger craft.The larger craft is a SHIP.Therefore a captains gig is a BOAT.A PT is a BOAT.Even at 40 tons--it could be transported on deck.So too a PG, if you really needed to.One doesn't generally hoist a destroyer on deck for transport...So taking your uncle's description of "a boat" into account I would be inclined to suggest that you look to the smaller craft such as the PTs and/or the single PG that was there that day.
Good luck and let us know how it turns out.
From FAQ US NAVY Website: Ships Present at Pearl Harbor, 0800 7 December 1941 Related Resource: Pearl Harbor Attack
The commissioned U.S. Navy ships in the list below are sorted by type and hull number, for example New Orleans (CA-32) is found in hull number order under heavy cruisers. For the purposes of this list, yard craft assigned to the Fourteenth Naval District and other small non-commissioned craft are not included. In addition, Pearl Harbor is defined as the area inside the nets guarding the harbor entrance.
Ships marked with an asterisk (*) were within twelve miles of the island of Oahu but were not actually within Pearl Harbor as defined above. Locations of these ships are indicated. Ships marked with a number symbol (#) were sunk or destroyed during the Pearl Harbor attack. All of these were later raised and rebuilt except for Arizona, Oklahoma, and Utah. Oklahoma was raised but not rebuilt.
The U.S. carriers were not at Pearl Harbor. On 28 November, Admiral Kimmel sent USS Enterprise under Rear Admiral Willliam Halsey to deliver Marine Corps fighter planes to Wake Island. On 4 December Enterprise delivered the aircraft and on December 7 the task force was on its way back to Pearl Harbor. On 5 December, Admiral Kimmel sent the USS Lexington with a task force under Rear Admiral Newton to deliver 25 scout bombers to Midway Island. The last Pacific carrier, USS Saratoga, had left Pearl Harbor for upkeep and repairs on the West Coast.
Battleships (BB)Pennsylvania(BB-38) (in drydock) #Arizona(BB-39) Nevada(BB-36) #Oklahoma(BB-37) Tennessee(BB-43) #California(BB-44) Maryland(BB-46) #West Virginia (BB-48)
Heavy Cruisers (CA) New Orleans(CA-32) San Francisco (CA-38)
Light Cruisers (CL) Raleigh(CL-7) Detroit(CL-8) Phoenix(CL-46) Honolulu(CL-48) St. Louis(CL-49) Helena(CL-50
Destroyers (DD)Allen(DD-66) Schley(DD-103) Chew(DD-106) * Ward(DD-139) (patrolling Channel entrance to Pearl Harbor) Dewey(DD-349) Farragut(DD-348) Hull(DD-350) MacDonough(DD-351) Worden(DD-352) Dale(DD-353) Monaghan(DD-354) Aylwin(DD-355) Selfridge(DD-357) Phelps(DD-360) Cummings(DD-365) Reid(DD-369) Case(DD-370) Conyngham(DD-371) Cassin(DD-372) (in drydock) Shaw(DD-373) (in floating drydock) Tucker(DD-374) Downes(DD-375) (in drydock) Bagley(DD-386) Blue(DD-387) Helm(DD-388) Mugford(DD-389) Ralph Talbot(DD-390) Henley(DD-391) Patterson(DD-392) Jarvis(DD-393)