If he had met some scary fish, he would immediately return to the surface

Question

Is the conditional used correctly? I'm referring to a past event which, in this part of the story, hasn't occurred yet.

The context is Tom's first deep-sea diving lesson.

Even though the sea was calm and the sun was high in the sky, Tom was shaking with fear. If he had met some scary fish, he would immediately return to the surface. After taking a deep breath, he dived in the water.

---> Since he really met some scary fish (he saw a shark - it is told in the next paragraph of the story) the 3rd conditional can't be used. On the other hand, since the sentence refers to the past, NOT to the present or future, the 2nd conditional isn't correct.

That's why I used a mixed conditional but I'm not sure whether it is used correctly or not.

Answer 1

Your hypothetical "if he had met..." is a counterfactual. It means he didn't meet any scary fish.

You only need a simple hypothetical "If he met any scary fish, he would return..." You might also want to frame this hypothetical in his plans at the time of the narrative. You mean "He planned.." or "He'd been told..." or "He decided..."

He decided that if he met any scary fish, he would return to the surface immediately.

Answer 2

No, "had met" doesn't work. It's either the past of the past, or an unreal past, neither of which fit the situation since it's real, and the future of a past time.

So let's start with the words to describe Tom's intent in that moment:

If he meets any scary fish, he will immediately return to the surface.

Since we're reporting what happened in the narrative past, we backshift these verbs just once:

If he met any scary fish, he would immediately return to the surface.

So that's a correct version.

Answer 3

Also, possibly subjunctive, ... though this seems not contemporary... "If he were to meet any scary fish..."

Answer 4

No, it’s not correct. Close, though. The second clause needs to be “would have,” rather than “would,” to match the tense, which sounds like past subjunctive to me but could also be present perfect subjunctive.

If you use the conditional in the first clause, the second clause is contingent on the same condition, and should also be in the conditional to match:

If he would meet some scary fish, he would return to the surface.

This makes sense if you’re describing his standard operating procedure or something like that. So, one context where this sounds natural and idiomatic to me is:

Every day, he used to dive into the lake. If he’d see some scary fish, he’d come right back up to the surface.

This describes an event that actually happened, on occasion, over a period of time in the past.

Another way to express a similar concept is with the subjunctive mood, indicating that this is a hypothetical or counterfactual situation.

In the previous example, if whoever we’re talking about had never met a scary fish, it would be a counterfactual clause in the past subjunctive, and the dependent clause would be a past conditional. (Observe that if [he] had never met is a present perfect subjunctive and would be is a present conditional. This is very similar to your example, but works for me while the other doesn’t, possibly because the other example sounds counterfactual, and this is not.)

If he had met any scary fish, he would have returned to the surface.

An example of a hypothetical situation with the future subjunctive (which is actually sarcastic):

I’ll be going diving soon. I promise, Mom: if I meet any scary fish, I will return to the surface immediately.

Note that the first example says “some scary fish” because it’s implied that there were some, and the second and third examples say “any scary fish,” because there either definitely were none or none are expected.