On March 25, 1915 USS F-4 (Submarine #23) while on a target practice exercise with the other three F class submarines stationed at Honolulu, submerged at 09:15, she would never resurface under her own power. Concern began about noon when the F-4 had not returned as the other boats had done and a search and rescue mission was immediately mounted.

First contact with the lost boat was thought to have been made later that day, although there was no proof that the object found was indeed the F-4. The object was lying at about 300 feet a mile and a half from the entrance of Honolulu harbor. There were no sounds coming from the submerged object and efforts to raise it with grappling hooks failed.

The navy was concerned, but felt it was possible to rescue anyone who may have survived. They estimated the air supply should last at least a day, but not much longer than that, so every effort was made to get to the wreck of the F-4. More equipment was brought to the scene and several attempts were made to raise the boat, however every attempt failed, lines broke or just slipped off the submarine, within two days the hope that the crew had survived faded, no sounds had been heard from the boat and by now the air had probably run out.

While they continued to hope, everyone knew the twenty-one man crew had perished, and now the rescue mission was a recovery mission. This turned out to be far more difficult than first thought. The navy apparently did not have equipment capable of lifting a submarine from the bottom, and the depth was too great to send divers down to properly attach lines. In fact they struggled day after day to try and get a line under the F-4, but again all attempts failed.

On April 1 a team of navy deep diving experts from New York were ordered to go to the F-4 and help in the recovery effort. Chief Gunner's Mate Frank W. Crilley was the first member of the team to reach the wreck. During the survey of the F-4 it was noted that the superstructure was caved and the hull was filled with water, but this was probably caused by seepage, no definitive answer as to the cause of the loss.

There had been many experts who had voiced their opinions as to the cause of the loss, a battery explosion, engine malfunction, battery malfunction, the submarine hit a submerged object and the hull had been breeched, but of course this was all pure speculation since nobody had seen the wreck and no messages had been received from anyone on the F-4. Sadly this seems to be a common practice, and is worse today, people who just talk to hear their head roar with no evidence at all.

There had been those who claimed the F class submarines were unsafe or just a poor design, in fact some even claimed that ALL of the navy's submarines were unsafe, imagine that! At least two of those who had doubts about the safety of the F class were now at the bottom of the ocean inside the F-4. Electrician 2nd Class George L. Deeth wrote in a letter to friend;

"The F-4 has been the unluckiest boat in the flotilla. Since we arrived here it has been just one thing after another." He later spoke of a battery explosion that had occurred that injured a number of crewmen, he summed it up by saying; "We were all lucky enough to come out of it in one piece instead of being picked up in sections."

The other man who had doubts about the F-4 was none other than her commanding officer, Lt. (j.g.) Alfred L. Ede. He wrote in a letter to his brother on Mar. 22, just two days before her loss;

"This is not a very exciting place, but enough happens to the boat to at least keep up interest. I just came back from Pearl Harbor on Thursday where I have been for ten days having a new motor put in. Previous to that we had a hydrogen explosion in the battery. Engine breakdowns and etc. So there is something doing all the time.

Take the mere trifle like today, down fifty feet and no bottom below and water trickling in through one of the valves. That does not give us a thrill anymore. In fact if the whole boat should vanish in smoke, I don't think I would be terribly astonished." Such were the thoughts of those who served in the F-4, critics back in Washington felt much the same way.

The reason for the loss was still unknown when salvage operations were underway, and on Apr. 17 the F-4 nearly claimed another victim. One of the divers from New York, Chief Gunner's Mate William F. Loughman, became entangled in some of the many lines which were attached to the submarine, Fred Crilley volunteered to go and rescue Loughman, who was at about 250 feet. At the risk of his own life Crilley worked until he was exhausted, but after over two hours freed Loughman from the death grip he had been in, for his extraordinary heroism, Crilley was awarded the Medal of Honor.

Further diving attempts at such deep levels was discouraged by the navy, the dive team from New York having already set several new diving records, but the near loss of two men gave pause the officials higher up and it was decided to try and drag the F-4 to shallower water. This was done, and finally the wreck was raised using pontoons on Aug. 29, just over five months after she sank.

In October the navy released the report on the loss blaming corroded rivets in the forward battery tank for allowing water to enter the boat, this plus poor diving qualities added up to disaster. Once the extra weight of the water was added to the boat, she did not respond to the rudder and just continued to sink. What happened inside the boat is not known for sure, some had hoped that a crewman had the time and the presence of mind to write down what had occurred inside the doomed submarine, even pointing to Lt. Commander Sakuma of the Japanese Submarine #6 which had sunk on Apr. 15, 1910, before he was overcome by the toxic fumes, Sakuma wrote a final report about what happened to his submarine and how to avoid the problem in the future, the letter was found on his body when the boat was raised.

However there seems to have been no time for writing on the F-4, the navy's report states that six men died at their posts in the forward compartment, while fifteen others made it into the engine room and died when the bulkhead failed due to the pressure. The report sums up the actions of the crew in this way:

"From the facts established, we find the accident resulting in disaster to the U.S.S. submarine F-4 on March 25, 1915 was not due to carelessness negligence or inefficacy on the part of the officers or men of the vessel and that furthermore the personnel remained at their respective stations until all effective means employed to avert the disaster impending had failed and thereafter sought refuge."

Henry R. Carso, President of the Electric Boat Company, the shipyard that had designed the F-4 disagreed with the findings and in a long statement came very close to blaming the crew for lack of care taken in maintaining the boat. He also claimed they had left several vent valves open which did not allow the ballast tanks to fill with air after expending the water ballast and he claimed that this was the primary cause of the loss.

It is true that these valves were left open, however the navy report claimed that water was being forced into the boat through the torpedo tubes by the increasing pressure, and it is not known how much water she had taken on before she began to make her final plunge. The crew may have been suffering from affixation from the chlorine gas from the wet batteries, caused by the leaking rivet, or she just went down so fast that they had no time to close them. Even if the tanks had filled with air it is unlikely this would have been able to overcome the additional weight of the water.

Carso concluded his remarks by saying;
"In the foregoing remarks there is no intention of reflecting on the unfortunate men who lost their lives in the vessel, but the fact that these valves were left open must not be overlooked." Corporate double talk in the finest sense, first blame those who died, and then deny you blamed them.

After the loss of the F-4 there was talk of removing the other three F class boats from service and indeed they were temporally removed from service on Sept. 5, 1915 just days after the F-4 was raised. However they were rammed by by the USS Supply while they were at Honolulu, all three boats were damaged, but later returned to active service. One of them USS F-1 was sunk on Dec. 17, 1917 after being rammed by USS F-3, nineteen of her crew perished.

The F-4 was examined and left to rot, in 1940 her remains were used as fill for a trench off the submarine base at Pearl Harbor.