OC resident here.

As mentioned, the only true beachfront Marriott is the RC Laguna Niguel (just south of Dana Point). Your next best bet for best ocean views likely is the Marriott Newport Coast Villas, but it’s not beachfront. The Montage Laguna Beach is a rare beachfront property, but the beach, while very dramatic, is rather small and can be quite crowded. Even the Resort at Pelican Hill is across PCH from the beach (even a bit farther than from the nearby Newport Coast Villas).

Everything else in the Marriott portfolio is either harborfront (Lido House Newport Beach or Laguna Cliffs Marriott in Dana Point) or located across PCH from the beach (Marriott Newport Coast Villas).

You also can consider the Marriott Newport Beach located next to the Fashion Island shopping center, as it’s just a 10-15 min drive to the main Newport beaches or harbor or the Crystal Cove state beach near the Newport Coast Villas.

You also can consider the Marriott Newport Beach Bayview...which has views of the back bay estuary but still is a 10-15 min drive to the closest of the Newport beaches or Crystal Cove.

I also highly recommend spending at least a day walking around and/or at the beach in Laguna Beach (different from Laguna Niguel, which is another 10-15 min drive south). It’s one of the most charming beachfront towns in SoCal, even if it’s toruisty as hell over summer. It really clears out in mid Sept through the beginning of May or June. But lots of great restaurants, galleries, and hillside views. And a nice beach. If you love Laguna and don’t mind stepping outside Marriott or any chains, the Surf and Sand is beachfront and is quite pleasant.