Weligama vs Mirissa vs Unawatuna — which south coast base is best and what is each one actually like?

I live on the south coast and know all three well. Honest breakdown.

Weligama:
The most functional and genuinely liveable of the three. A proper town with local shops, markets, and restaurants beyond tourist menus. The bay is wide, sheltered, and safe for swimming. Best beginner surf in Sri Lanka (consistent, sandy-bottomed small waves). The longshore bay means you can walk the beach for an hour. Accommodation from budget to mid-range. Less "pretty" than Mirissa but more real. Great for: couples, surfers, people who want a local feel.

Mirissa:
The prettiest of the three — a curved headland bay with a coconut-covered island. The most photogenic sunsets on the south coast. However: significantly overtouristed and party-focused in high season. Bars play loud music until 2–3 AM, beach crowded in January–March. The beach itself has a rip current at the eastern end — swimming requires care. Best for: people who want Instagram scenery, nightlife, and whale watching access. If you value sleep and quiet, book away from the beach strip.

Unawatuna:
Closest to Galle (8km), most convenient for day trips to the fort. A horseshoe bay with calm, turquoise water — genuinely the safest swimming on the south coast. Snorkelling at Japanese Garden reef 5 minutes by kayak: excellent. But: the most developed and most crowded of the three. The beach has had serious erosion issues. Accommodation overpriced relative to Weligama. Best for: snorkelling, families, people using Galle as a cultural base.

Tangalle (as an alternative): Genuinely quieter, bigger turtle nesting beach, more authentic town. Worth considering if you want to escape the Weligama–Mirissa corridor entirely. 1 hour further east.

My recommendation for a couple: Base in Weligama for 3 nights, day trip to Mirissa for whale watching and sunset, day trip to Unawatuna for snorkelling.