Wireless data over 100 miles of open ocean

Any theories on how to establish a broadband-speed (i.e. 4MB or faster) wireless link across approximately 100 miles of unobstructed ocean? Antennas at either end cannot be more than 100 feet above sea level.

Thank you for your suggestions.

100 foot towers are not compatible with curvature of the earth.

high speed long links are not compatible with the requirement to acknowledge receipt of packets.

you need a satellite link

No possibility of ground wave propagation in the 900Mhz range?

I will assume the answer to that is no for now. If one antenna was constrained to a height of 90 feet, how high would the other need to be if it were 100 miles away?

I really need to avoid satellite due to latency issues. Cable is also currently not an option. 3 or 5 meter reflectors would not be a problem.

900 MHz doesn't have "ground propagation" like AM broadcast 500 Khz to 1500 KHz.

In theory 500 foot at both ends will give you line of sight clearance, but they have to be higher for Fresnel zone clearance, and on has to be 20 % even higher to avoid direct out-of-phase reflection.

Reflectors only increases the gain, it won't overcome the above problem.

High latency satellite, or nothing at all...Pick one.