So... I'm a Tactical officer & I'm Captain 1.
I've learned the torpedo skill (capped grade, 9) that allows you to teach HY3 to your BOffs. When I go to the powers vendor it's just not in the list.

I understand some BOffs can't lean/use it, but it's not even in the list.

What's going on?

Try clicking on the bridge officers name that you want to have high yield 3 in the status screen ("U" by default), and using the "Train" button on the bottom.

You need to train it yourself, go into the character window for the BOFF that you want to train and there should be a button at the bottom of the window?

*edit* bah tgreth beat me to it

The powers vendor is not abilities that you train, thats on your own character sheet. Hit 'U' select your character, select status and look at the bottom, you will see a tab marked 'Train" select the ability to train and then the officer to train it too and there ya go.

You don't go to the power vendor. You press "U" to open your skills screen, select the officer, and there should be a "Train" button there somewhere.

Hi- I have a two part related question- Once you train a BO in HYIII can you train other tactical BO's in it as well? Or can you only TRAIN a BO in that Skill 1 time?

Another question is what happens if I train HYIII to a BO that has HYI as his ensign level skill then put him in a tactical LC Post- Does that mean he gets BOTH HYI and HYIII in his available powers buttons?! How does that work?

You can train the skill as many times as you like.

and yes you would have both HY I and III, there is a short global cooldown (about 10-15seconds) that prevents you using them straight after each other though.

Aha! I didn't even know skills were in there, thanks guys!