Robost Wifi networking for Controls Application

How robust is Wifi communications? My application would be to link various Remote IO from a PLC over a Wifi network to a main controller? The environment is very hostile (weather). This application would be to use a WIFI or mesh WIFI network on the back of a large Workboat to read pressure sensors, angle sensors, and other control sensors. It may also, in the future, be upgraded so that at some points, we have Analog and Digital output.

There are no plans for protocols such as Profisafe running on the network, but this may happen in the future. Currently we will need Profinet(Siemens), TwinCat(Beckhoff) or Ethernet/IP (Allen Bradley). My options are either put in a Fibre network with Scalance or Cisco switches which will require a lot of cabling, or plan a robust wifi network.
WIFI is just not robust enough. With any WiFi network there is latency, which varies for many reasons. Your control system would suffer from unexplained funcgionsl errors.