Wifif network to scientific instrument

Question

I want to connect my laptop to an Ethernet connected scientific instrument that's in a test tank in the yard outside my office. It has a fixed ip and subnet mask and sends data at about 25Mbps. It's currently in a bucket by my desk connected via CAT5 to a USB Ethernet dongle, which allows me control of the instrument and normal internet access at the same time. This all works but I want to move it to a larger tank outside about 15m away.

My employer will not want the instrument on the work Ethernet, so I cant patch it into the office Ethernet (also it's high data rate, so I'd be really unpopular with my colleagues).

Running a cable would be tricky, but I do at least have power at the tank. Ideally, I want to go from instrument->wifi router->about 15m air to my office->wifi something inside office window->CAT5->USB cat5 connector in laptop. This is so that the existing laptop wireless adapter can continue to connect to normal internet, I'll also probably have an Ethernet switch in the office so that I can access the instrument from more than one computer. A second best alternative would be instrument->wifi router->about 15m air->laptop's normal wifi, and use CAT5 on the laptop for normal internet. Plan C would be a long CAT5 cable, but it will get mangled when I shut the window and not last long.

Thanks for any suggestions.