Enjoy the hotel buffet for variety and speed; for a local option, On Lok Yun (classic Thai breakfast) opens ~6:00am and offers a nostalgic, inexpensive start.
Explore limestone karsts, caves and James Bond Island or canoe through sea caves; tours typically run 8:00am–4:00pm and include guide and lunch—book with a reputable operator and confirm exact pickup time.
If you have energy, visit a weekend night market (e.g., Phuket Weekend Market) for snacks and souvenirs; markets generally run into the late evening on weekends.
Board your return international flight (or connect via Bangkok). For cheap business class, check flexible one-way/business deals and consider mileage upgrades—book sooner for best premium fares.