Access to the Calanques National Park is being controlled this summer due to damage to the ecosystem caused by the burgeoning numbers of visitors, and due to increasing fire risks. The Calanque de Sugiton which used to attract up to 2,500 people a day is, being limited to 400 entries. Pre-booking one of the free passes is via the new app. Details here: https://www.marseille-tourisme.com/en/blog-marseille/summer-access-sugiton-calanque/ This regulation is in force until 31 August. Reservations are all cancelled by email in case of fire risk.
Access roads to Morgiou, Sormiou and Callelongue are closed to traffic daily until the end of August; pedestrians though are admitted. You can also visit Sormiou by car if you have a reservation to eat at Le Chateau, the only restaurant down by the sea. Your reg no is checked at the barrier and then you can drive down the vertiginous narrow road with the most astounding views of the Mediterraean. After eating you can have a paddle on the sandy beach and admire the ‘cabanons’ that were so popular with weekending Marseille families. (You can read a review of ‘Le Cabanon’ in my Books section – it gives a splendid overview of these traditional communities).
Alternative ideas:
Boat trips are available from La Ciotat, Cassis and Marseille. For instance, a standard 3-hr tour from the Vieux Port to see 12 calanques costs an adult 32€ on a 150-240 seater boat. Or there are motor boats, a catamaran, sunset cruises, tours to include swimming/snorkelling – lots of options.
The navette maritime – water taxi – can take you down to Les Goudes from the VP, until 25 September. It’s just 8€ one way and you can hike to your heart’s content from the tiny port. An hourly service.
aixcentric 
Thanks for that information!