Hali fishing on the Banks in September is largely a hit and miss show. Most years by this time (earlier actually) they have begun to slide off into the deep (as in far beyond our ability to reach them) where they spend the winter.
From what we saw out there this year, they are doing that later than "normal". Early September we had no problem tagging limits out on the Big bank. End of the first week, we trolled up 14 in a little better than an hour. As the month wore on, the numbers began to slide quite noticeably! I took clients out to the Shallow Spot last weekend. Trolled there for a tad better than 6 hours. Results: 5 hali's and a handfull of smallish springs. The coho had obviously moved off, as they were nowhere to be seen. So, as they were our secondary target, we went in search thereof. Off to 14 Mile - a few small and scattered schools, no hali's. Picked up a few, one or two hatch coho to the bag, then in to 10 Mile. Smaller schools, no springs, no hali's. A couple more to hand, and in to 7 Mile. A few larger schools, and fini the day on them. Then the run inshore. 2.5 miles off Beale, coho everywhere! Didn't drop gear (we were late and limited), but saw loads of jumpers. Marked the schools and travelled with them for a spell - moving at 4.5 knots towards the Sound, coming home...
That was my last trip out there for the season. In my opinion, the hali's have indeed begun their dissapearing act for the year, the returning springs and coho have chiefly departed the Banks for their natal rivers, leaving but feeder springs about in any real numbers.
That said, there have been some years when we've tagged hali's well into this month. Perhaps the operator you refer to knows one or two of the special places they will linger, and can get you into a few. Hope he does!!
Good luck, have FUN, and hope to be reading your successfull report shortly!!
Cheers,
nog