I would suggest reading the CF threads on WiFi
antennas and connections so you can get an idea of the equipment
that works best on cruising boats. And, of course, anything you are dependent upon a "provider" for maintaining and monitoring his WiFi
server, the less reliable a continuous unbroken connection will be in general.
Beyond that, the only "sure" way is to invest in the same equipment
and services the "big boys" use like those mega-yachts you see with up to half a dozen gigantic domes perched on their 5-spreader rigs. If you intend to make serious money
in a serious business like Forex or other "options" markets then you probably need to be ready to spend serious money
on your equipment to be able to compete.