According to the Palestine Times, Israel has changed the area that Gaza fishing boats can go.
It used to be 9 miles out to sea, but (apparently for security reasons) Israel has reduced it to 6 miles in the north and south of Gaza, but to make up for the loss of area it increased the distance for the middle of Gaza to 12 miles.
The Gaza fisherman's union rejected the changes, in protest of the six mile limit at the northern and southern borders.
Which means that they still cannot go further that six miles anyway in the north and south - and they are not taking advantage of the additional three miles newly available to them.
As far as I know, Israel never allowed a 12 mile area to be fished since the blockade was started.
Ironically, last summer when Israel increased the fishing zone in central Gaza from six to nine miles, fishermen complained that the additional area was not suitable for fishing - and they demanded a 12 mile zone.
Now they have it and their own union will not let them use it.
(h/t Ibn Boutros)