An optimistic view on the AHTS market future: http://www.marinelink.com/news/handling-anchor-supply418182
This article appears to mix AHTS with Subsea vessels, but the market for specialized subsea vessels have not suffered near as much as the general AHTS market.
The market for modern high powered (>15000 BHP) AHTS and large PSVs, which can also perform other duties, such as ROV support, simple subsea work, field support, wind farm tender etc. will likely improve, but the market for small and old AHTS and PSVs is a different case. Scrapping would be a solution, but there is a reluctance to go that route, since the scrap value of small vessels are very low.
The GoM market tend to be separated from the general world market due to the requirement for US flag, at least for simple OSVs. Most of the high end market is covered by foreign flag vessels and thus part of the world market.