I don't beleive you will find any instances of Fleet Boats refueling at sea merely to continue operations. Although the USN lead the world at that time in underwiegh replenishment techniques, these were limited to the surface forces and submarines were independent operators.

Running out of fuel before expending torpedoes was a fact of life and Fleet Boats often would conduct "Double-Barreled Patrols" where they would replenish at a different base and then return to their patrol area. The patrol would end only when they returned to their home base and the parts of the patrol would be lettered (Patrol 2A & 2B for example) for administrative purposes. SH4 allows you to simulate this particularly later in the war when US island-hopping often creates new bases, you can refuel and replenish there but your patrol does not formally end.

Tenders where very valuable strategic assets and were not generally pushed into the forward areas until their absolute safety could be assured and a pretty thorough infrastructure was needed to support submarine operations. Running a base using junks and 45-gallon drums is very unlikely but SH4 is just a game afterall and you can make it work, more power to you.

Good Luck.

I would rather see the option of getting a tow. Massive renown hit of course.

But when you are 500 miles from Pearl and you suddenly realize that Fleet Subs aint got no oars....

There was one instance where a crazy (my opinion) captain pulled up in a nice little cove in Japanese waters, surfaced, took a couple of stern torpedoes on deck, floated them around to the bow and reloaded them there. Scared the crew to death. I bet he was called a few choice names.

Wonder what Admiral Lockwood said to him?

As for getting a tow, if you are in Japanese waters with no US ships anywhere near, you may get a tow but you won't like where you're going!:-?