Hi,
Personal experience:
1. Voice activated devices -

, terrible. Getting "voice activated" in most "needclearanswer" situations. (Mr. Murphy's law).
2. Marine VHF - better, but too big and heavy.
ICOM stuff - not reliable antennas, break often.
3. Marine VHF with separate, combined mic / speaker device - more convinient.
4. Simplest PTTs, Cobras, Motorola, HYT with 5-8 km range. 40-80 $ per two pcs with charger. For me this is th best solution. Very small, light weight, reliable stuff.
5. Crew has to learn well, and understand, that these devices are not for a show and playing "US navy seals against US mariners"... However, those guys really know how to use radio communication...
rgds,
Andrei