Having trouble keeping up with all Mayor Bill de Blasio’s new scandals? Here’s one you might have missed: A member of a board that chose the firm to run city ferries is an investor in that company and sits on its board.

As a report in The City revealed last week, Mark Patricof is on the boards of both the city’s Economic Development Corporation (a quasi-public agency controlled by the mayor that oversees and funds NYC Ferry) and Hornblower Holdings, which runs the ferry service. Patricof is also an investor in Hornblower.

That sure has at least the appearance of a conflict. Yet because the EDC is technically not a city agency, Patricof isn’t answerable to the Conflicts of Interest Board.

And agency ethics rules don’t ban board members from investing in or serving on the boards of companies that do business with the EDC, although they’re supposed to abstain from any deliberations, transactions and votes.

EDC claims Patricof has not been involved in Hornblower-related business with the city since he joined its board in April. Yet, as Reinvent Albany’s Alex Camarda puts it: “An EDC board member should not have a substantial financial stake in any company doing business with EDC.” He calls that a “blatant” conflict.

It would certainly be understandable, after all, if average New Yorkers wondered if such a conflict explains why the costs of the ferry service have blown through the roof. As the Citizen Budget Commission has reported, the city loses an average of $10.73 on every ferry ride.

And no, City Hall doesn’t (as the old joke goes) make it up on volume. Actually, de Blasio’s ferries carry fewer people in a year than the subways do in a single day.

Worse, as the EDC’s director of ferry operations testified Wed­nesday at a City Council hearing, the agency hasn’t collected data showing that low-income riders use the subsidized service. So there’s a fair chance the subsidies are going to help riders who can well afford to pay their full fares.

Sure, such sleaze and waste might seem like just more of the same from de Blasio. But he has 2½ years left in office. How much more of it can New Yorkers take?