Blue whale watching in Mirissa — is it ethical, which operators are good, and what are the realistic chances of seeing one?

I help run a marine wildlife operation on the south coast. Here is an honest picture:

Best months for blue whales: November to April, with December–March being the peak. Blue whales migrate through the southern waters of Sri Lanka — Mirissa sits directly on this route. The concentration of blue whales here is genuinely among the highest on Earth. This is not marketing.

Realistic probability of sighting:
- December–March: 70–85% chance of sighting at least one blue whale
- April: 50–65%
- Outside peak season: Much lower — operators may still run trips but honest ones will tell you
- Dolphins (spinner, bottlenose): Near-certain on almost any trip

Ethical operators vs irresponsible ones:
The difference is immediately visible. Responsible operators:
- Approach whales at slow speed from the side, not head-on
- Stop engines when within 300m
- Do not position the boat in the whale's path
- Limit viewing time to 20–30 minutes per whale
- Usually run smaller boats (10–20 passengers)

Irresponsible operators chase whales with multiple boats at speed — you've seen this footage. When booking, ask specifically: "Do you follow the MMSL/IUCN whale watching guidelines?" If they look blank, find another operator.

Boat choice: Smaller boats (catamaran or rigid inflatable, 10–16 people) get closer viewing, quieter engines, and can stop faster. Large commercial catamarans (40–60 people) are more stable but the experience is more chaotic.

Trip duration: 4–6 hours typically, going 15–20 nautical miles offshore. Bring seasickness tablets — the swell can be significant.