The documents available to me only cover events up to Aug. 9; other ships may have joined from (or left at) other ports later on. Please scroll down to the bottom of this page for possible, additional ships.

Commodore (as far as Algiers) B. Grant was in Harold L. Winslow (Captain Rockower), Vice Commodore was the captain of Catrine.

Commodore Grant feels that Harold L. Winslow is suitable as Commodore's ship for a short passage only, as there was no accommodation for him and his staff. The signal staff had to be berthed in the ship's hospital, while the Commodore was kindly given the captain's own cabin. Other than that, the ship was well equipped with all the latest appliances and the "Master was most keen in his duties and did all in his power to assist Commodore. The officers were very young and inexperienced but considering their very brief sea experience, carried out their duties in as satisfactory a manner as could be expected".

Average speed: 8.6 knots.

The convoy was turned over to Captain Taylor, U.S.N. at 11:00B on Aug. 10, joining from Bizerta with William G. Fargo (name actually given as William Fargo, but I'm guessing it should be William G. Fargo) which had previously been detached from the convoy to embark him. Commodore B. Grant and his staff then disembarked off Algiers at 07:40B on Aug. 11.

19 ships were present from Port Said, Aug. 3:

For the U.S.:
Catrine - arrived Chesapeake Bay Aug. 28-1944
James Duncan - voyage from Abadan, arrived Chesapeake Bay Aug. 28-1944, arrived Baltimore Aug. 29.
William Hawkins - voyage from Khorram Shahr, arrived Baltimore Aug. 29.
John W. Griffiths - voyage from Calcutta, arrived Chesapeake Bay Aug. 28-1944, arrived Baltimore Aug. 29.
George Sharswood - voyage from Khorram Shahr, arrived New York Aug. 27-1944.
Albino Perez - voyage from Cochin.
Henry Adams - voyage from Calcutta, arrived New York Aug. 27-1944.
Keith Palmer - voyage from Busreh, arrived New York Aug. 27-1944.
Mark Keppel - voyage from Calcutta, arrived Chesapeake Bay Aug. 28-1944.
James B. Hickok - voyage from Busreh, arrived New York Aug. 27-1944.
Charles Nordhoff - voyage from Busreh, arrived Chesapeake Bay Aug. 28-1944, arrived Baltimore Aug. 29.
Harold L. Winslow (Commodore's ship to Algiers) - voyage from Calcutta, arrived New York Aug. 27-1944.

For Augusta:
Empire Elaine - voyage from Bombay, parted company on Aug. 8, see below.
Fort La Prairie - voyage from Suez, parted company on Aug. 8.
Ocean Valour - for Augusta / Ancona, parted company on Aug. 8.
Samlea - voyage from Calcutta, for Augusta / Bari, parted company on Aug. 8.
Wallace E. Pratt - voyage from Abadan - parted company for Augusta on Aug. 8.

Fort St. James - voyage from Lourenco Marques, for Cagliar / Bizerta (parted company for Bizerta Aug. 9).

Dagrun - voyage from Taltal, for Casablanca / Gibraltar.

13 joined from Alexandria at 12:00C on Aug. 4:

For the U.S.:
Salawati - voyage from Glasgow, arrived Chesapeake Bay Aug. 28-1944, arrived Baltimore Aug. 29.
Robert Howe - voyage from Busreh, arrived New York Aug. 27-1944.
William D. Burnham - voyage from Vizagapatam, arrived Chesapeake Bay Aug. 28-1944, arrived Baltimore Aug. 29.
Frederick C. Hicks - voyage from Calcutta, arrived New York Aug. 27-1944.
Eloy Alfaro - voyage from Abadan, arrived New York Aug. 27-1944.
Edam - voyage from Liverpool, arrived Philadelphia Aug. 28-1944.
Kronprinsen - voyage from Lourenco Marques, arrived New York Aug. 27-1944.

For Augusta:
Samleyte - parted company on Aug. 8, see below (see also GUS 47).
Francis Lewis - parted company on Aug. 8
Samsacola (Captain Godley) - voyage from Lourenco Marques, for Augusta / Naples, parted company on Aug. 8. This ship lost a man overboard at 18:15 - date illegible. HMS La Malouine, which was adjacent to the ship when this happened, searched for an hour to no avail.
George Weems - voyage from Abadan, parted company on Aug. 8.
Ocean Trader (Captain Bonham) - parted company on Aug. 8.

F. T. 15 - later parted company at Malta, see below.

At 17:45B on Aug. 7, an enemy aircraft identified as a JU 188 by HMS Jonquil flew across the front of the convoy in position 35 04N 17 29E at low altitude, but made no attempt to attack the convoy.

28 joined from Augusta at 08:15B on Aug. 8:

For the U.S.:
William G. Fargo - voyage from Naples, arrived New York Aug. 27-1944. (As mentioned, this ship was detached to pick up the U.S. Commodore from Bizerta).
Robert Treat - voyage from Naples, arrived New York Aug. 27-1944.
David L. Swain - voyage from Naples, arrived Chesapeake Bay Aug. 28-1944.
Erastus Smith - voyage from Naples, arrived New York Aug. 27-1944.
Joseph Francis - voyage from Naples, arrived New York Aug. 27-1944.
Lawrence J. Brengle - voyage from Naples, arrived Chesapeake Bay Aug. 28-1944.
Samuel Moody - voyage from Naples, arrived Chesapeake Bay Aug. 28-1944.
Daniel H. Hill (name given as Daniel Hill in document) - for Hampton Roads.
Joyce Kilmer - voyage from Naples, arrived New York Aug. 27-1944.
Magdala - voyage from Bari, arrived New York Aug. 27-1944.
Jotunfjell - voyage from Taranto, arrived New York Aug. 27-1944.
Israel Putman - voyage from Castellamare, arrived Chesapeake Bay Aug. 28-1944.
Joseph Gale - voyage from Naples, arrived Chesapeake Bay Aug. 28-1944.
Alexander Mitchell - voyage from Naples, arrived Chesapeake Bay Aug. 28-1944.
Oliver Hazard Perry (name listed as Oliver H. Perry in document) - voyage from Piombino, arrived Chesapeake Bay Aug. 28-1944.
Richard Jordan Gatling - voyage from Naples, arrived Chesapeake Bay Aug. 28-1944.
John S. Casement - voyage from Naples, arrived Chesapeake Bay Aug. 28-1944.
Barendrecht - voyage from Bari, arrived New York Aug. 27-1944.
Backhuysen - voyage from Brindisi, arrived New York Aug. 27-1944.

Samuel Gorton - destination not known.
Joseph McKenna - destination not known.
William M. Eastland - destination not known.

For Algiers:
Egret
Pronto

For Oran:
Serula
Benjamin H. Latrobe

Mayo Brothers - for Bizerta (left convoy Aug. 9)
Robert Dale Owen - for Oran (listed as Robert D. Owen in document).

while 10 parted company for Augusta at 06:30B that day in 36 20N 15 25E:
Wallace E. Pratt, Empire Elaine, Fort La Prairie, Ocean Valour, Ocean Trader, Samleyte, Samlea, Samsacola, Francis Lewis, George Weems.

For info, Ocean Trader left Augusta again for Taranto the next day (Aug. 9-1944), while George Weems and Fort La Prairie left for Brindisi, and Samlea and Ocean Valour for Bari (final destination of the latter was Ancona). Samleyte, Samsacola, Empire Elaine, Wallace E. Pratt, and Francis Lewis left Augusta for Naples on Aug. 10.

1 joined from Malta, 1 left for Malta at 13:15B on Aug. 8 in 36 30N 14 22E:
Saltcreek joined (left for Bizerta Aug. 9).

F.T. 15 parted company.

7 joined from Bizerta at 16:00B on Aug. 9:

For the U.S.:
U.S.S. Yukon
Horace Mann (see Convoy GUS 47) - arrived Chesapeake Bay Aug. 28-1944, arrived Baltimore Aug. 29.
Howard A. Kelly (listed as Howard Kelly in the document) - arrived Chesapeake Bay Aug. 28-1944.

For Oran:
Dornoch
Joel Chandler Harris (listed as Joel C. Harris in the document).

Empire Cato - for Algiers (this ship had arrived Augusta from Faslane Docks, Scotland on Aug. 8-1944 and sailed the same day).
U.S.S. Maumee

while 3 left for Bizerta at the same time:
Saltcreek, Mayo Brothers, Fort St. James.

68 had joined, 14 had parted company
Total ships now in convoy: 54.

Other ships that arrived the U.S. around the same time as GUS 48, and may have been in this convoy:

The following arrived Chesapeake Bay on Aug. 28-1944:
Egbert Benson, David Thompson (both from Casablanca), Lavoro (from Gibraltar), Samyale (from Lisbon), Fort Orleans (from Malaga), Katy, Smith Thompson and Esso Concord (all from Oran).
Lavoro and Samyale arrived Baltimore on Aug. 28, Esso Concord and Egbert Benson arrived Baltimore on Aug. 29, while Katy arrived New York on Aug. 31.

Norsol arrived Philadelphia on Aug. 28-1944 (voyage from Casablanca).

Additionally, the following ships arrived New York on Aug. 27-1944:
Arizonan, Cartago, Empire Airman, Toltec (all from Naples), Britannia, British Pride, Kong Haakon VII (all from Algiers), Fort Connolly (from Lisbon), Topdalsfjord (from Bizerta, see Gus 47) and Megna (from Calcutta).

Lavoro, Samyale, Fort Orleans, Fort Connolly and Megna had left Gibraltar on Aug. 13-1944.

Escorts:
HMS Jonquil (S.O.) and La Malouine joined off Port Said at 16:00C Aug. 3 - left off Bizerta at 16:00B Aug. 9.
HMS Bryony and Myosotis joined off Alexandria at 12:00C Aug. 4 - left off Bizerta at 16:00B Aug. 9.
U.S. Escorts joined off Bizerta at 15:00B on Aug. 9 (names unknown).

Related external links:
Chronological list of GU convoys (with the returning UG convoys).

Liberty Ships - Alphabetical list.

List of Liberty Ships by Hull No. - Includes info on the men for whom the ships were named (from Wikipedia).

Empire Ships - Also has a listing of the "Sam"-ships, ex Liberty Ships that came under the British flag (and other Liberty ships).

Fort, Ocean & Park Ships