Tonga, swimming with whales

My boyfriend and I are going to Tonga in early- mid July, for 11 days. We really really want to swim with whales.
Can anyone tell me if you have to go to Vava'u to do this or is it possible form Tongatapu or Eua.

We were originally planning on going to Vava'u but we are now having second thoughts as the accomodation seemed quite limited in choice- either really budget or really expensive. Are there any good "mid-range" options?

Is 11 days too long to spend between Eua and Tongatapu? We are quite good at relaxing with a book etc but want like some activity as well.

Any advice welcome,

Thanks

Whale watching can be done in any of the island groups in Tonga.
For accommodation options on any island group, check out: http://www.tongaholiday.com/?page_id=1260

July is a bit early for the whales, you will not be able to find any operator who will guarantee a swim. However in Vava'u the operators will be out looking for them until they arrive. It is possible to 'bargain' a little with the operators there as well since there are no guarantees. If you are lucky enough to find a whale it is even more special to swim with the first one, they are normaly more quiet in the early season before mass whale swimming begins.
I would suggest you use dolphin pacific diving and whale watching for the whaleswim and Mystic Sands for the accomodation.

Safe travels :)