Just submitted the intent to submit form (yay!) but I am not sure what to do with the acknowledgements.

My second supervisor was awful. She was going through a tough time when the PhD started and I thought it would pass but only got worse (her life got back to normal, though!). She left me hanging in the air when I needed advice and decided to micromanage me when I really needed some headspace to figure things out. Add in some generally inappropriate behaviours, e.g. commenting on my dating life and things weren't great. Tried to speak about it, got shouted at, so sucked it up.

Buuut, she is besties with my main supervisor, so I couldn't drop her. Main sup was more focused on helping sup2 by furthering her career with a supervised PhD student (me) than helping me. She was okay. After I figured out what I needed, she followed my suggestions, that is fine. Supportive enough.

They both recently admitted they cannot supervise my theoretical work as neither understands it. Which kills the focus of my thesis and its whole point. There is enough left to submit but it is going to be one hell of a viva ("Why did you not do X?" "I did X but my sups didn't understand it and I was not allowed to include it" - need to work on that!).

I need a nice way to acknowledge them, as not having acknowledgements will be seen as an insult by them (I know...). I just cannot come up with anything polite that expresses my true feelings.

Help! Any suggestions?

Acknowledge them. It is just acknowledgements and you gain nothing by ignoring them but annoy them by not. Every thesis acknowledges the supervisors and they at least tried to help. They might not have been perfect but the acknowledgements is not the place to vent your frustration.

That is my point - I will have to acknowledge them but how to I do it politely without lying? I am looking for suggestions for how to word it.

Hi

I had this exact same issue but I only had one supervisor and she has more or less gone awol for the last year of my Ph.D. I acknowledged her as vaguely as I could, I tried to twist the truth as best as I could by saying that she had provided guidance and support and blah blah, I basically lied but I just kept the whole thing vague, like rewt said above, it's only acknowledgements and you have nothing to gain by pissing them off.

I have a friend whose supervisor didn't help him much, so he included him in a big list without any 'special' thanks. I've reworded it slightly but here is what he wrote:

"Throughout these three years, many scholars advised me and provided invaluable assistance with my doctoral research. First and foremost, I would like to thank my academic supervisor, XXXXX; the thesis examiners, XXX and XXX; and the assessors for my transfer of status, XXX, XXX and XXX."

So, as you can see, he barely says anything detailed about his supervisor. Maybe that is helpful for you?

Thank you, that is really helpful! Might go with Nesrine87's suggestion.

Although that will piss them off - there are some very fragile egos at work, they're looking for a lot of praise. Which is why do not want to lie too much - sup2 has another PhD student right now and is starting to treat him the same way she did with me ("because it worked"). I don't want to reinforce her delusions, otherwise I would just praise them to the moon and back and move on.

Which I might still do in order to avoid any negative consequences but I thought it worth asking if someone more polite than me might have a suggestion ;)

I had a similar issue. Don't think of it as lying. I mean, they went thru the motions and tried to fulfill their role. Keep it formal. A bit like acknowledging your funder or the gatekeeper or stakeholder with whom you actually had no personal involvement. I said something like: I thank my supervisors x x and x for their advice and support during my PhD. Just a formality... If you want to be more heartfelt about family, friends and whatnot, then you can do that in the following sentences. Anyone who knows the situ can read between the lines if that's important to you!

Congrats!

It's the end, but not yet over. You still need them for the defense, and other examation related issues.

"I am grateful to my Supervisors X, XX, XXX for their guidance over the three years.

Then go on to others!