The US Army's Logistics "Navy" in WWII.

[Big Orange]

According to this website the US Army (that came under the Department of War, at the time) had a surprisingly sizable bluewater fleet of ships in the Second World War that were primarily used for logistics (including hospital ships) and also served secondary combat roles (like mine laying). These ships served an integral role in the Atlantic and Pacific campaigns, but by 1950 with the formation of the Department of Defence, this little known flotilla of boats and ships were dispelled; absorbed into the US Navy or scrapped altogether. Since the US Army's ships are largely forgotten about and were unsurprisingly overshadowed by the US Navy at the time, the US Army's "navy" was known as the "Ghost Fleet" and remain unknown to most people (like the US Army Ballistic Missile Agency's outlandish but serious plans for a moon base formulated in the 1950s). The British Army had a logistics fleet as well and I've seen an old book on the subject once in my local library not so long ago.

[Sea Skimmer]

Yup by number of floating hulls the US Army has the largest fleet in WW2; though this does count a lot of marginal things like powered pontoons. The USN had greater tonnage. Pre WW2 plans said the USN was supposed to take over all military shipping in wartime. But the pace of mobilization was such that the USN didn’t have nearly enough officers and men to take everything over. So the US Army fleet actually expanded as the war went on.

Today the US Army still does have some vessels of up to several thousand tons, mainly for unloading bigger ships at places with no ports or insufficient depth of water. Basically they are modern LSTs.
http://www.globalsecurity.org/military/ ... /lsv-a.htm

[Big Orange]

OK, the guy hosting the website I linked has an excerpt about US Army in recent times still having bluewater boats around in landing support roles:

There are still Army transport vessels. They are little known, but apparently that was the case back when the world was at war and the great Army fleet got little notice. They plug along doing those necessary jobs without a great deal of publicity and recognition. They carried cargo, troops and fought in Vietnam. They are prepared to support rapid deployment today. I suspect even other soldiers are often surprised to find exactly what an 88K does. I wonder if they are still the only troops with authorized footgear of "tennis shoes" or today's equivalent. Today's fleet is limited in scope, but still interesting.
In 1999 I spent a dampish October morning looking at traffic leaving the Chesapeake for the Atlantic from my motel balcony in Virginia Beach. I saw a line of small Navy vessels that looked a bit odd. When I got my glasses on them I realized they were not Navy. They were some of the newer landing craft that are much more ship like. I then noticed the Army insignia and realized I was seeing Army vessels at sea. They were all flying a brilliant red flag with some sort of gold device that I realized had to be that of the Transportation Corps. These were probably operating out of Fort Eustis.

Link

And a contemporary novelist (Christian Bauman) has used Army boats in his novels and has a small page on them here (with a photograph depicting a old looking LCM-8 craft loading up what looks like Army/Marine infantrymen).

[Deathstalker]

The ships don't load at Ft. Eustis, they were most likely loaded in Newport News, Portsmouth or Norfolk. I've seen the Ghost Fleet on the James River, but haven't seen it in 10 years but I know it is a lot smaller as ships are sent to the breakers.