Similar to missiles, but it would be shot in a straight line that could be manually aim and fire, it would be cloaked and slow. The ship that is in the receiving end would have an audio alarm when torpedoes are fired and the more it got near, the quicker it gets similar to the sonar sound. Then, when the torpedo is almost on you they would uncloak and arm a powerful warhead.
The fact that you can manually fire means that you can shoot in the future point of contact, leading the ship. But since torpedoes can't change direction, if the ship abruptly changes corse, it will evade them.
The cloak is nice because of flavor but also so point defense can't shoot it straight away. It will still have a chance when it is almost connecting, and I think it would be fair to uncloak almost on top, even if point defense destroy the torpedoes the explosion would still do some damage to the ship most exterior parts.
This should be an expensive but deadly weapon and it would fit the flavor of the cloaked ships that are already on the roadmap. I can almost see it, the deadly "submarines" cloaking themselves and approaching the ship, to then launch torpedoes and haul ass.