I thought I heard at some point on the BBs that HTC wanted to add subs. Could be mistaken though.
He did mention it in an interview a few years ago, prior to the announcment of what was called then "Tour of Duty" before it changed to "Combat Tour".
IIRC, Dale's dad served onboard a submarine, though don't know if it was during the war but I think it may have been. It was the same interview where Dale also expressed the idea of also adding player controlled paratroopers to fight it out in 'bunker-like' complex for captures. Unfortunately, at the time this was all placed on the back burner for CT but now that CT has itself been placed on the back burner, the idea of the submarines and player controlled paratroopers will be revisited.
ack-ack
