Here are the best two description concering PT Boat operations in WWII...
Originally conceived as antiship weapons, PTs were publicly, but erroneously, credited with sinking Japanese warships during the early months after Pearl Harbor. During the long Solomons campaign, they operated usefully at night and times of low visibility against Japanese barge traffic in the "Slot." Throughout World War II, PTs operated in the southern, western, and northern Pacific, as well as in the Mediterranean and the English Channel. Some served off Normandy during that invasion. Though their primary mission continued to be seen as attack of surface ships and craft, PTs were also used effectively to lay mines and smoke screens, to rescue downed aviators, and to carry out intelligence or raider operations. Almost all surviving Elco PTs were disposed of shortly after V-J Day. One Elco boat, PT 617, survives at Battleship Cove, Fall River, Massachusetts.
PT boats tactics and operations
PT boats operated mainly at night for two reasons:
First, with their small size, low profile, and high speed, they could use the night to get very close to the enemy without being detected (which larger surface vessels could not), and could quickly maneuver and escape once detected (which submarines could not). They could also operate very close to the beach in shallow waters (which both larger surface vessels and submarines could not) and used this ability to ambush or hide, perform intelligence missions, commando team landings, rescue missions (mostly of downed airmen), and even attack targets ashore with gunfire, including daring penetrations into protected enemy harbors.
Second, in daylight, attack aircraft and torpedo bombers could do a better job in attacking enemy shipping and with less risk, and the PT boats themselves were in danger of being detected and attacked in daytime. So the PT boats naturally concentrated most of their activity in night operations in coastal waters, in which they had advantage over other vessels and aircraft, but where there was a lower risk in daylight operations, they did that too.
What I couldn't find after an extensive search was....the number of enemy ships sunk by PT Boats that would justify giving a Stealth Ability in TOS. Frankly I couldn't find any confirmed sinking of an IJN warship in WWII of DD size or larger. I like the concept of the PT Base Eric..but don't see how you can give it a stealth capability. This would support my earlier email to you about what happened in a recent TOS 3 game involving a PT encounter that destroyed a Trans stacked with CVs, BBs, CAs, and DDs.
Sully