Walk beside the Ria Formosa
Begin along the waterfront rather than looking for a checklist of monuments. The view takes in moored fishing boats and the lagoon channel, with the island beyond. Notice the small working details along the edge: Cabanas' relationship with the water is part of the attraction, not just the route to the beach.
Use this as an easy first-day outing while you learn where the boat departures, food shops and your accommodation sit in relation to one another. A stroll before breakfast and another near the end of the day can feel quite different. Leave enough space in the plan to stop when something catches your eye.
Make the island the main event
A boat crossing separates the village from Cabanas' ocean beach. Give a beach visit its own block of time so the boarding, walk over the island and return do not feel like interruptions. Travelling light helps if you are carrying equipment or sharing the outing with young children.
Settle the return arrangements before heading along the sand, and keep what you need for the day with you. The lagoon-facing waterfront and the ocean shore offer different experiences. Choose the designated beach access rather than trying to improvise a route across the channel or dunes.
Spend a day in Tavira
Tavira adds a different setting to a Cabanas stay: the Gilão river, historic streets and the castle area. Make it a town day rather than trying to fit another island outing into the same schedule. Pick a small number of heritage stops, then leave time for lunch and a riverside pause.
Plan the journey back before setting off, especially if dinner is booked in Cabanas. If your group enjoys different things, use the river as a meeting point while some explore uphill. You do not need to see every church or museum for the outing to add worthwhile variety.
Choose a lagoon activity with a clear purpose
A nature-focused boat outing is different from a simple beach crossing. When comparing activities, look at the time spent travelling, whether you land anywhere and how much explanation is included. A short, focused trip can be a better match for a relaxed stay than the longest route on offer.
For birdwatching, ask about the route and the experience of the guide rather than expecting a list of guaranteed sightings. If water sports interest you, discuss ability, equipment and conditions with the operator. Keep one unbooked day in your stay so the weather and your energy can shape the plan.