After World War II, Nieuwe Haven Naval Base was built on reclaimed land east of the Nieuwediep, and the Nieuwdiep's source and mouth were dammed off.

Nieuwediep started out as a trench in the Wadden Sea, called Het Nieuwe Diep, which translates as 'the new canal'.

In the seventeenth and eighteenth century it became increasingly difficult for big ships to regularly sail to the Dutch cities on the Zuiderzee.

Many ships therefore anchored in the Roadstead of Texel, where a lot of transloading was done by vessels that brought the cargo to Amsterdam and other cities.

The importance of a protected base for the Dutch navy and commercial shipping near Den Helder was stressed by the Fourth Anglo-Dutch War.

A plan to make a useful and safe harbor for warships in the Nieuwediep was then made by: Captain W. May, equipage master of the Amsterdam Admiralty; C. Brunings, inspector general of the rivers; Surveyor B. Goudriaan, L. de Berge and P. Haage.

[2] On 5 September 1781 orders were given to create a stone dam east of the Nieuwdiep that would guide the ebb flow for 348,500 guilders.

Nevertheless, the first effects were shown when in August 1782 the bump in the mouth of the Nieuwediep was found to have been lowered by 1–1.5 feet.

[4] In June 1783 33,000 guilders were spent for a dam, lijdam, of 500 m stretching SSW from the southern entrance of the Nieuwediep, creating a funnel together with part 3.

[6] A specific advantage was that ships from the south, loaded with perishable goods like fruits, could unload at Nieuwediep.

In the winter of 1784–1785 there were 150 ships at Nieuwediep, among them merchant men with a draft of 18–20 feet laying somewhat at the bottom of the harbor.

In 1792 a repair facility and sophisticated careening place called 'Het Nieuwe Werk' was established.

In 1799 the Anglo-Russian invasion of Holland led to the capture of Nieuwediep and the Nieuwe Werk and the loss of about two dozen ships.

In the subsequent Vlieter incident, a cornered Dutch fleet of eight ships of the line and four frigates then mutinied and surrendered without firing a shot.

In 1811 Napoleon Bonaparte visited Den Helder, and ordered the construction the biggest naval base and maintenance shipyard of the Netherlands, as well as an extensive ring of fortifications.

Nowadays, Willemsoord is a maritime attraction park and new city center for Den Helder.

During the siege, the Dutch fleet in Den Helder, the so-called squadron of Texel consisted of; the ships of the line: Prince (80), Zoutman (80), De Ruyter (80), Evertsen (80) and Doggersbank; the frigates Meuse (44) and Ijssel (44) (both with French crews); the corvette Venus and the Brig Irene, as well as the French brig Iréne.

In port and not ready were the ships of the line: Amsterdam (80), Brabant (76), Jean de Witt (68) and Rotterdam (68), and the frigates Aurora / Dageraad (32) and Maria Reijgersbergen (32).

After the regained independence, the Dutch government was just as eager to press the commercial as the military facilities.

On 17 October 1817, the Danish ship Christiana, Captain Hans Corssen, entered the lock, and continued to the partially complete inner harbor to be repaired.

Loading and unloading ships (except transloading) had been forbidden during the French occupation, and Amsterdam succeeded in prolonging this ban till 1851.

This was accelerated by the connection to the railway system, and the arrival of the SMN, whose East Indies ocean liners were simply too large for the Noordhollandsch Kanaal.