A progress report for 2006 concerning our research on underwater communications is given. We shortly describe field demonstrations of a high performance acoustic link. All our published reports on electromagnetical, acoustical, and optical methods for underwater communication are given from 2000 - 2006. Proposals of modem design for acoustical communications are presented together with an estimated degree of performance and tactical use. Starting from our naval forces tasks in both national and international operations, we formulate and discuss briefly nine different situations or visions for operative use of acoustical underwater communication. In all of them, the underwater link is either necessary or gives added value. An important conclusion of our research is that the modern communication techniques allow for streaming transmission of speech, data, and text over ranges of 80 - 100 km in a sound channel and if a fairly potent transducer is used. We already demonstrated this for ranges up to 60 km using a less powerful transducer. At short range less than a km, or using a vertical uplink, streaming videao (64 kbps) should be possible.