I would consider how you are asking the question and what you will do with the information...
The title of the poll is 'poor experience due to lack of interest or bad management' however in your post you are talking about 'verbal or physical abuse'?
Waving such a big wide stick isn't going to get the information you need, nor do I expect through an anonymous poll without any verification of the respondents. The Chamber are heavily involved in Cadet Welfare, both on a professional and personal level. However I wouldn't expect them to treat the results of your 'fact finding' in an open forum as a good representation of what is happening during a Cadet's sea phase.
I think your intentions are good, but this isn't the way to go about it.