samedi 16 mai 2015

Ocean Business 2015

On 14-16 April 2015 was held the conference Ocean Business 2015 (
I think it is a very good opportunity to reactivate this blog about underwater instruments as there was a lot of new products exhibited.

Let's begin with a first one very interesting: SonarBell developed by SALT (Subsea Asset Location Technologies Ltd). SonarBell is the underwater acoustics equivalent of the Luneberg lenses used in radar.

dimanche 8 septembre 2013

Bottoming II

If you want to dig in mechanical considerations for bottoming, here is the link to a good paper:


For the first article, let's speak about an interesting capability that a new submarine could develop: bottoming.

The primary capabilities to assert in the design of a new submarine are the submarine depth ratings.

There are four depths to take into account:
  1. Design depth is the nominal depth listed in the submarine's specifications.
  2. Test depth is the maximum depth at which a submarine is permitted to operate under normal peacetime circumstances, and is tested during sea trials.
  3. Never-exceed depth is the maximum depth at which a submarine is allowed to operate.
  4. Collapse depth is the submerged depth at which a submarine's hull will collapse due to pressure. 
These depths were useful in the context of deep water submarine warfare (blue-water navy).

However, looking at he recent geopolitical tensions,  the submarine warfare is moving to coastal zones and estuaries. Submarines are becoming part of the green-water navy.

A new and interesting capability to develop for a submarine is thus the bottoming: the ability to land the submarine on the bottom of the water layer.

A submarine with such capability could wait on a zone with a compliant bathymetry and, as such, would be a real silent hunter.

A "classic" submarine is able to bottom only if the bathymetry is a homogeneous plan with a small slope.

Recently, the department of Marketing and Communications at DCNS has released a good joke about this subject on Youtube.

Here is the video. Enjoy!!



This blog is dedicated to underwater technologies and instruments.

I expect to keep you informed of the last products developed for the sectors of Defence and Oil&Gas.