During this period, in the Dutch Republic political power was contested between the ruling States faction and the Organgists who wanted to make William III of Orange stadtholder.

In the Dutch navy, this was a slow process, as its officers were very popular naval heroes, whose expertise was sorely needed in the fight against France.

After the Battle of Texel in 1673, Schepers was appointed lieutenant-admiral of the Admiralty of the Noorderkwartier on 6 October, succeeding the deceased Jan Meppel, despite never having served in the navy before.

In 1676, he first commanded, with Vice-Admiral Jan Jansse van Nes, a flotilla blocking the French corsair base Dunkirk and then supported the Danes against Sweden with a squadron.

When Cornelis Tromp became lieutenant-admiral-general of the confederate Dutch fleet, Schepers, on 25 February 1678, succeeded him as lieutenant-admiral of the important Admiralty of Amsterdam.

The States General of the Netherlands appointed Schepers to head a commission, together with Cornelis Valckenier and Simon Velius, to formulate proposals for the improvement of the readiness of the Dutch fleet.