US most definitely working hard to address this issue over the last 30 years, and I would worry in US place, because as of recent examples, US still doesnt have proper detection of diesel subs.
You talk as if you know what you are talking about, which you do not.
The 'proper' detection method of any submarine is sonar. When a diesel sub is submerged, it runs on batteries, so at this point, it is essentially an electrically driven vessel. It would be neither fast nor long distance capable nor long duration underwater. However, it does not mean it cannot be detected via sonar.
Sonar detection, just like radar detection, is a two-way street. We have a transmitter, a body, and a receiver. When someone say it is difficult to detect an electrically driven submarine or a diesel boat, he really mean it is difficult to detect a diesel boat via
PASSIVE detection of acoustic signals generated from the boat itself. If an active sonar transmission, or 'ping', is interrupted by said diesel boat and produces an echo, said diesel boat is detected. Just like how an aircraft interrupt a radar transmission travel and produced an 'echo' on the radar scope.
There are non-acoustic methods towards diesel boats in anti-submarine warfare (ASW):
- Magnetic Anomaly Detection (MAD)
In shallow waters, the diesel boat have very limited maneuvering room, as in depth wise, so its magnetic disturbance can be detected because of its operating depth, and depending on where in the Strait, the diesel boat can even be visually detected from the air...
Submarines | Hormuz
Iran & Submarines
The depth of Strait of Hormuz (depth of 82 feet to 131 feet) is deep enough for ships, but is shallow for the submarines. The shallow waters and strong currents of the Strait both hamper and aid submarines the water provides noisy background conditions that help cover up the sound of a submarine, but the shallow waters make the submarine more likely to be visually identified from the air or surface of the water. The confined waters and strong currents of the Gulf make the Strait of Hormuz an extremely hazardous place for even experienced submariners.
Another method is through powerful data processing of satellite imagery.
You read correctly --
SATELLITES.
Asia Times Online :: China News, China Business News, Taiwan and Hong Kong News and Business.
Satellites might see subtle undersea disturbances caused by submarines, watch wave patterns on or beneath the sea surface, or detect subtle variations in ocean temperature.
A moving sub produces
INTERNAL waves while a surface vessel produces external wake.
From the same source...
A US Navy oceanographer from Australia, Paul Scully-Power, who became the first oceanographer in space, flew on the space shuttle Challenger (STS - 41G) in 1984. The US Navy later admitted that the mission had successfully detected the undersea or internal waves generated by a submarine which had been tracked successfully at relatively shallow depths. This was deemed, "incredibly important to us" and was reported by the Washington Post in 1985 - quoting a senior US Navy admiral at the time.
ScienceDirect.com - Marine Geology - Progress of internal waves along submarine canyons
This indicates that internal waves (mostly tidal in period) are advancing up the submarine canyons or rarely downcanyon. Because the data come from canyons off California, the East Coast of the United States, and the Hawaiian Islands and include depths to as much as 3,500 m, it is suggested that these canyon internal waves may be worldwide.
Gravity Wave Modeling
Internal waves generated by a submarine
Submarines generate internal waves in two ways: by flow over the body of the submarine and by turbulent motions in the wake of the submarine. CPI is developing computationally fast models of internal-wave production for body and wake generated internal waves, which also follow internal-wave propagation through a realistic ocean, from the submarine to the sea surface.
These underwater waves sort of 'percolate' upward towards the surface in a predictable manner and the closer to the surface is that generator of those waves, the more prominent and detectable those patterns.
A diesel boat can also generate transient noise, even as faint and brief as a closing hatch or a dropped object
INSIDE the boat, that can be picked up by an experience sonarman.
For example...
Submarine Frequently Asked Questions
What clothes do you wear?
When in port, crew members wear regular Navy uniforms. At sea, members wear one-piece blue coveralls called "poopy suits." They are very comfortable to wear and reduces the number of clothes the sailor has to bring to sea. Submarine crews usually wear sneakers or other soft bottomed shoes when at sea, as sound quieting and stealth are always foremost in a submariner's mind.
Even water flowing over the skin can be detected...
Acoustic signature - Wikipedia, the free encyclopedia
Hydrodynamic noise: noise generated by the movement of water displaced by the hull of a moving vessel.
Do some research...