Arrive at your Colombo hotel (choose a central 4–5★ with a pool and spa) and drop bags; freshen up after travel to be ready for a high-energy day and night.
Short tuk-tuk tour to Gangaramaya Temple (open generally 6:00am–8:00pm) and a stroll along Galle Face Green for photos and street snacks — a cultural contrast before the party starts.
High-end seafood lunch known for Sri Lankan crab; reserve ahead — great to kick off the celebration with unforgettable food (open midday to late afternoon, reservations strongly recommended).
Recover from travel and prepare for the night with a swim and a short spa treatment (most hotel spas open ~9:00am–9:00pm); booking ahead recommended for groups.
Head to a rooftop bar to watch the sunset and enjoy cocktails — a great photo op and warm-up before dinner (rooftops typically open 5:00pm–midnight or later).
Head to a licensed casino in Colombo (many operate inside major hotels; typical crowd peaks late evening). Casinos generally operate late-night (often ~8:00pm–4:00am but check venue hours, entry rules and dress code).
Hire a private boat for cruising, island stops, snorkeling (where allowed) and a lively on-board party — typical charters run in the afternoon and last 2–3 hours; book a licensed operator.
Return to your private villa or beach club for a themed BBQ, drinks and a hired DJ — perfect bachelor party energy; arrange permits/noise rules with your host location.
Group surf lesson in Weligama/Hikkaduwa (beginner-friendly spots) — surf schools typically run morning lessons 7:00am–11:00am; great hangover-cure and bonding activity.
A group recovery massage at a recommended spa (many operate 9:00am–9:00pm); book in advance to ensure your group is accommodated and refreshed for travel.
Head back to Colombo in a private van; Colombo traffic can add time so aim for a buffer — Colombo airport (Bandaranaike) is ~1–1.5 hours from central Colombo depending on time of day.