17 Sep, 1943
With her trials and initial training completed USS Aspro (Lt.Cdr. H.C. Stevenson) departs New London bound for Pearl Harbour.

18 Oct, 1943
USS Aspro (Lt.Cdr. H.C. Stevenson) arrives at Pearl Harbour.

24 Nov, 1943
USS Aspro (Lt.Cdr. H.C. Stevenson) departs Pearl Harbour for her 1st war patrol. She is ordered to patrol off Formosa.

28 Nov, 1943
USS Aspro (Lt.Cdr. H.C. Stevenson) toppes off with fuel at Midway.

1 Jan, 1944
USS Aspro (Lt.Cdr. H.C. Stevenson) ends her 1st war patrol at Midway.

15 Jan, 1944
Lt.Cdr. W.A. Stevenson takes over command from his brother Lt.Cdr. H.C. Stevenson who has developed problems with his eyesight during Aspro's 1st war patrol at was disqualified for sea duty after an eye examination.

3 Feb, 1944
After a short training period at Pearl Harbour USS Aspro (Lt.Cdr. W.A. Stevenson) departs this base for her 2nd war patrol. She is ordered to patrol north of Truk, Caroline Islands.

15 Feb, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) torpedoes and sinks the Japanese submarine I-43 (2230 tons, offsite link) about 280 nautical miles east-south-east of Guam in position 10º23'N, 150º23'E. (see map)

28 Mar, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) ends her 2nd war patrol at Pearl Harbour.

22 Apr, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) departs Pearl Harbour for her 3rd war patrol. She is ordered to patrol off the Palau's.

14 May, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) and USS Bowfin (Cdr. J. Corbus) torpedo and sink the Japanese army cargo ship Bisan Maru (4667 GRT) about 90 nautical miles north-west of Palau in position 08º55'N, 133º42'E. (see map)

15 May, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) torpedoes and sinks the Japanese troop transport Jokuja Maru (6440 GRT) about 175 nautical miles north-west of Palau in position 10º10'N, 131º48'E. (see map)

16 Jun, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) ends her 3rd war patrol at Fremantle, Australia.

9 Jul, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) departs Fremantle for her 4th war patrol. She is ordered to patrol in the South China Sea.

16 Jul, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) toppes off with fuel at Darwin, Australia.

28 Jul, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) torpedoes the grounded Japanese auxiliary gunboat Peking Maru (2288 GRT) aground off Vigan Point, Luzon, Philippines in position 17º33'N, 120º21'E. The Peking Maru remains aground and is declared a total loss and abandoned. (see map)

18 Aug, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) ends her 4th war patrol at Fremantle.

10 Sep, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) departs Fremantle for her 5th war patrol. She is ordered to patrol in the South China Sea.

2 Oct, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) torpedoes and sinks the Japanese merchant cargo ship Azuchisan Maru (6886 GRT) in South China Sea west of Luzon, Philippines in position 18º25'N, 120º32'E. (see map)

14 Oct, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) ends her 5th war patrol at Saipan.

25 Oct, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) arrives at Pearl Harbour.

21 Nov, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) departs Pearl Harbour bound for Saipan.

28 Nov, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) suffers a fire and is forced to return to Pearl Harbour for repairs.

13 Dec, 1944
USS Aspro (Lt.Cdr. W.A. Stevenson) departs Pearl Harbour for her 6th war patrol. She is ordered to patrol off Formosa.

2 Jan, 1945
USS Aspro (Lt.Cdr. W.A. Stevenson) torpedoes and damages the Japanese landing ship Shinshu Maru (8170 GRT) south of Formosa Strait in position 22º42'N, 119º14'E. The damaged Shinshu Maru is sunk the next day by aircraft from the US Task Force 38. (see map)

11 Feb, 1945
USS Aspro (Lt.Cdr. W.A. Stevenson) ends her 6th war patrol at Pearl Harbour. She was now sent to the Hunters Point Navy Yard for a major overhaul.

20 Feb, 1945
USS Aspro (Lt.Cdr. W.A. Stevenson) arrives at the Hunters Point Navy Yard to begin her overhaul.

31 May, 1945
With her overhaul completed USS Aspro (Lt.Cdr. J.H. Ashley, Jr.) departs the Hunters Point Navy Yard bound for Pearl Harbour.

25 Jun, 1945
USS Aspro (Lt.Cdr. J.H. Ashley, Jr.) departs Pearl Harbour for her 7th war patrol. She is ordered to patrol south of the Japanese home islands.

13 Aug, 1945
USS Aspro (Lt.Cdr. J.H. Ashley, Jr.) ends her 7th war patrol at Midway.