That's the kicker.
EoJ pointed out that a single battle could take 5 hours - I'm assuming it was in reference to any two ships captained by two experienced yet still novice players on opposite sides. Also could be small fleet engagement by two veteran players.
EoJ did not, however, mention that a single turn could take 5 hours (keeping in mind that one SFB turn was ~1 minute of "real time") provided the conditions were right - I want to say somewhere in the neighborhood of 6-8 ships on the board with 2-4 players, at least 1 novice.
Nor did EoJ mention that a single impulse (1/32 of 1 turn; ~2 seconds of SFB "realtime") under the right circumstances could take up to 5 hours to conclude - this would be some kind of large fleet (10ish ships per fleet, 2-3 fleets) engagement with many players (somewhere around 4 players per fleet), a crap load of drones/plasma on the board, fighters, shuttles, PFs, etc... The kind of engagement where at least one non-playing person sits back and plays judge just to help the game keep going forward...
Yeah, it was a blast.
And for the love of Pete, NEVER sneeze towards the board...
The Czar
P.S. You say back in the day as if it was some long forgotten time... Was only a decade ago or so when I stopped playing SFB in earnest... That's only like yesterday, really...