Good question. As mentioned in the other reply, 2.4GHz radio is clearly not in this list. So you need an extra underwater interface, with probably a special protocol since 1Mbps is not attainable.
Options:
- LF radio communications (carrier < 8kHz, only up to 1 kbaud)
- Acoustic waves, read
http://www.edn.com/contents/images/60930.pdf
- Visible light communication, read
http://www.araa.asn.au/acra/acra2004/papers/schill.pdf
I think the last options takes less time, and the components are cheapest and simplest, and the expected data rate is the highest.
Components for IrDA are commercially available for simple interfacing (free samples via maxim-ic.com):
www.maxim-ic.com, look for IrDA (MAX31xx series)
Limitation is that the remote control must be within a certain angle above your 'bug', because for large incident angles the air/water surface is reflective. To avoid that, you might want to immerse the rc.
If you are good at preamplifier electronics, I think you can improve on the 'standard' maxim receiver circuit in terms of both range and data rate. But building such an improved optical interface is a project in itself.
Does this help?
Marco