China's SSBNs might possibly be sent, from their main Yulin/Sanya/Hainan Island Base, north to operate in the protected East China Seas or Yellow Seas. But movement north would put them in closer range of Japanese and South Korean SSKs and Russian SSKs and SSNs. Very quiet, experienced US SSNs (that can range far and fast) might be the main hazard for Chinese SSBNs.
To make life even more difficult the SeaWeb sensors can be positioned in restricted waters so as to be just below a Chinese SSBN's maximum diving depth and above it.
THERMOCLINES NO COVER
(say 300 or 400m sonar).
may well "active" - hence able bounce off the hull and detect even subs that are hardly moving.
An SSBN switching its reactor to silent mode, while using battery powered thrusters, will not
totally hide it from active sonar.
usefully laid for long term use in restrictive waters (like the Yellow Sea, East China Sea and South
China Sea). Or, in addition to sonobuoys, they could be laid (especially air-dropped) on a shorter
term basis in front of the likely path of the SSBN.