In this area, we collect work that is not done every day. Below you can see the services of our underwater work:

  • Ship inspection
  • Bridge inspection
  • Habitat assembly
  • Respiratory protection work
  • Slide assembly
  • Ordnance recovery
  • Treasure recovery
  • Sound path control

Inspection of a suction dredger in the port of Hamburg

At the end of September, AQUA-NAUTIK GmbH received the order to inspect the 12 flaps of the Alexander von Humboldt suction excavator. The sediment that was dredged from the Elbe in order to maintain the water depth required for shipping is dumped into the North Sea via the flaps. There was evidence that sediment was being lost through leaking valves.

It was imperative to check this. In order to keep the costs for this inspection as low as possible, the inspection should be carried out during the time when the Alexander von Humboldt was stuck in storage for fuel. The time frame given to us was around 2 hours.

Alexander von Humboldt

With this order, all flaps had to be documented by video for the client. After a short briefing by the captain and his staff, we were able to start setting up the deployment site. The diver was brought into the water from the quay in a man basket. The flaps were sufficient for orientation on the ship's floor. A total of 14 flaps were inspected, 7 on the starboard side and 7 on the port side.

Apart from slight deformations on the seals and slight signs of wear on the flaps, nothing was found, these were not enough to cause the sediment to be lost. A final check of the propellers and rudders did not reveal any further damage. The client was able to follow the entire dive live in the emergency vehicle and finally received digital documentation. The Alexander von Humboldt left for her next mission just 30 minutes after our dive.

"Wood" - core drilling on a bridge in Lübeck

The inspection order that AQUA-NAUTIK GmbH was supposed to carry out in August 2015 on a Lübeck wooden bridge from 1936 required intensive preparation time. Various permits had to be obtained and completed in advance for this order. Various wood core drillings should be carried out to check the stability of the foundations and documented by video and photo. After the preparations had been completed and all permits had been received, the operation could start on schedule. First of all, the operational equipment, consisting of a floating diving unit, was transported to Lübeck by crane truck with the company's own low-loader and then launched into the water.

The next step was to start cleaning the wooden sheet pile wall. A suitable location for the best wood cores was discussed and carried out with the client. Various wood cores have been taken from the piles behind. The resulting boreholes were then closed again with locally manufactured hardwood cylinders and fixed in place. The wooden sheet pile wall was opened at various points and then closed again after the samples were taken. Because the tasks were carried out quickly and to the full satisfaction of the client, the divers were then deployed to another bridge for an inspection dive with video documentation.

Alexander von Humboldt

Treasure hunt

Cimbria" An emigrant ship that sank around 1880 about 20 nautical miles from Borkum was found by the treasure hunt company “Sea Explorer AG - Klaus Keppler”. After she acquired the rescue rights, the operation was planned down to the smallest detail and the management of the diving operation was transferred to Aqua-Nautik. The mission lasted over 3 months with two diving groups around the clock and made ample prey.

The best place to find out where and to what extent something can be viewed directly at Today the treasure hunter Klaus Keppler operates under: and is increasingly on the move in the Indonesian region. We wish you continued success in your search for and recovery of past artifacts.


Habitat assembly

A habitat was used to attach another deflector to the dredger so that the welding work could be carried out in the dry. After the habitat had been secured and checked for leaks, it was drained and the welding work was carried out in the dry.

Respiratory protection work

We also carry out this type of work with respiratory protection wherever the oxygen content is below 17%. A soot container for welding work was prepared, to avoid a dust explosion.


Slider assembly

Valve assembly and disassembly can be carried out both above and below water. Maintenance and repair work is carried out on slides that have already been installed. New installations must be adapted to local conditions and be suitable for underwater installation.


Ordnance Recovery

The recovery of ordnance is not our main business, although in our other tasks we occasionally come across such remnants of bygone days. Our metal detectors for underwater use are usually used for other tasks, such as locating lost work equipment in underwater construction.


Clay lane check and laying of Geotex mats

Mechanically laid clay lanes must be checked for connection and integrity (demolition) so that the later laying of mats and rock filling is also given over the entire surface. The buoyancy or misalignment of mats that are partially torn off or caused by suction and waves are restored by divers.

Petras Köln Porz-Zündorf
Niederkrüchten USA