Rathgama Lake is a 17.66-kilometre brackish lagoon on Sri Lanka's southern coast, connected to the Indian Ocean through a narrow channel near Hikkaduwa. It is fringed by mangrove forest, fed by the Gin Ganga river, and — most importantly for kayakers — almost entirely calm. There are no waves, no currents worth mentioning, and no boat traffic on the inner channels. If you have ever wanted to try kayaking but felt nervous about open water or unpredictable conditions, this lake is the answer.
This guide covers everything: what the lake looks like, which route to take, what you will see, what to bring, and how to book.
What Is Rathgama Lake?
Rathgama Lake (also written Ratgama Lagoon) is a brackish coastal lagoon — a mix of fresh river water and salt water from the sea. The salinity varies by season and location; the inner mangrove channels are almost fresh, while the outer lake near the ocean channel is more saline. The water is warm year-round (27–30°C), the depth rarely exceeds three or four metres in the paddling zones, and the bottom is sandy or silty.
The lake sits immediately behind Hikkaduwa's beach strip. From the main beach road you can see the ocean to the west and the lake to the east — they are separated by a narrow strip of land in places less than 200 metres wide. Despite being this close to one of Sri Lanka's busiest tourist beaches, the lake feels entirely removed. No jet skis, no music, no beach chairs. Just water, birds, and mangrove.
The Island Hermitage — a 113-year-old Buddhist monastery on an island in the middle of the lake — is one of the landmarks you pass on the longer tours. It has been a place of meditation for Western Buddhist monks since 1911 and is still active today.
Two Tours, One Lake
AquaTrek runs two guided kayak routes on Rathgama Lake, plus a flexible standard hour for those who just want to paddle without a fixed itinerary.
Sunrise & Wildlife Tour — Rs 3,000 per person
This is the one to choose if you have any interest in wildlife, photography, or simply the most beautiful version of the lake. Departure is at 6:00 AM and the tour covers approximately 4.5 km over 2.5 hours.
The route takes you through the inner mangrove channels first — narrow waterways where the canopy closes overhead and kingfishers fish from roots at eye level. Then out to open water across the middle of the lake, past the Island Hermitage, and back through a different channel on the return. You finish with a welcome drink and, on some routes, refreshments.
The reason this tour works at 6 AM is wildlife behaviour: birds are most active in the first two hours of light. Kingfishers are feeding. Herons are hunting. Brahminy Kites and Osprey are cruising above the open water. By 9 AM, the lake quietens significantly as the heat builds and birds move into shade.
Sunset & Banyan Tree Tour — Rs 3,000 per person
Departure at 3:30 PM, returning at sunset. This route is longer and more varied — it crosses more open water, stops at the famous Banyan tree that grows out over the lake surface, explores the mangrove channels near Dodanduwa fishing harbour, and ends with views of the sunset over the ocean from the harbour mouth.
The Banyan tree itself is extraordinary: a single tree that has grown so wide that its aerial roots have formed a small island of their own. Kayakers can paddle directly underneath the canopy.
The sunset tour is a good choice for couples and for travellers who are not early risers. Wildlife is less abundant than dawn but still present — especially herons and cormorants in the late afternoon — and the light at golden hour over the lake is excellent for photography.
Standard Kayaking — Rs 1,000 per person (1 hour)
For first-timers who want to try kayaking before committing to a longer tour, or for travellers with limited time. You paddle a defined area of the lake with a guide nearby. No fixed route — you go where you want within the safe zone. Available at flexible times throughout the day.
What Wildlife Will You See?
Rathgama Lake supports over 50 bird species and a healthy population of reptiles. Here is what appears on most tours:
Almost certain to see:
- Common Kingfisher — electric blue, seen diving from low branches in the mangrove channels
- Stork-billed Kingfisher — larger than the Common, orange bill, red legs
- Purple Heron — tall, usually still, hunting at the water's edge
- Little Cormorant — swimming with body low in the water, often diving
- Brahminy Kite — reddish-brown and white raptor, soars over the open lake
- Water Monitor Lizard — 1–1.5 metres long, swims between islands, often sunbathes on banks at eye level from the kayak
Frequently seen:
- Oriental Darter — the "snakebird," swims with neck above water, dries wings spread wide
- Grey Heron — large, grey, very still
- White-throated Kingfisher — turquoise and chestnut, often on power lines near the launch point
- Osprey (October–March) — hovering above the open water before diving feet-first for fish
- Lesser Whistling Duck — in groups, often roosting in overhanging trees
Occasionally seen:
- Macaque monkeys in the mangrove canopy
- Fruit bats (flying foxes) roosting in tall trees near the hermitage
- Traditional fishermen in outrigger canoes using cast nets — a technique unchanged for generations
Is Kayaking on Rathgama Lake Suitable for Beginners?
Yes, without qualification. The lake is calm, sheltered from wind by the surrounding vegetation, and has no significant current. The kayaks are stable, wide open-tops that are extremely difficult to capsize under normal paddling. Children as young as 5 have done the tour with a parent in the same kayak.
Before every tour, guides give a 10-minute briefing that covers: how to hold the paddle correctly, how to steer, how to stop, and what to do if you capsize (which essentially never happens, but it is good to know). Most guests are paddling confidently within five minutes.
The only guests who find it physically demanding are those who try to sprint the whole route. Kayaking at a relaxed pace on flat water is about as strenuous as a gentle walk.
What to Bring
- Reef-safe sunscreen — apply before you arrive. The UV index at 6°N latitude is high year-round
- Wide-brim hat — the open sections of the lake have no shade
- Light long-sleeve layer or rash guard — more effective than sunscreen for the upper arms
- Sandals or water shoes — you will step into shallow water at the launch point
- Small dry bag or phone case — provided by AquaTrek, but if you have your own, bring it
- Water bottle — also provided, but if you drink a lot, bring extra
What not to bring: a heavy camera bag, jewellery that can fall off, anything you cannot afford to get slightly wet.
How to Get to AquaTrek Rathgama Lake
AquaTrek is located at Dodandugoda Road, Dodanduwa — approximately 5–6 km from central Hikkaduwa town. The journey takes 15–20 minutes by tuk-tuk.
The easiest way to find it: message AquaTrek on WhatsApp at +94 72 130 1524 when you book and they will send you the exact location pin. Tuk-tuk drivers in Hikkaduwa generally know "AquaTrek Dodanduwa" — it is a well-known launch point.
There is free on-site parking for those arriving by car or motorbike.
How to Book
The simplest way is WhatsApp: message +94 72 130 1524 with your preferred date, tour type, and number of guests. Bookings are confirmed within a few hours — usually much faster. You can also use the online booking form on this website.
No advance payment is required. You pay on arrival, in cash. No payment if you need to cancel.
Frequently Asked Questions
How far in advance should I book? For weekdays, same-day booking is usually possible. For weekends and public holidays — especially between December and March — we recommend booking at least 2–3 days ahead. Sunrise tours fill fastest.
What happens if it rains? Light rain is fine and actually makes the mangrove channels particularly atmospheric. If conditions become unsafe, we reschedule or refund in full. We will never put guests on the water in weather that is genuinely dangerous.
Can I do a kayak tour if I cannot swim? Yes. Life jackets are mandatory for all guests and are fitted properly before departure. The water is shallow in most of the tour area. Non-swimmers do this tour regularly.
How many people can join a single tour? Up to 35 people in one session. Groups larger than 6 typically use multiple kayaks in convoy with guides at front and rear. We accommodate school trips, corporate groups, and family reunions regularly.
Is there parking at AquaTrek? Yes — free on-site parking at the launch point.
What is included in the Rs 3,000 price? Welcome drink on arrival, water bottle, life jacket, waterproof phone case, and a guided 2.5-hour tour. The Sunrise tour also includes tea after the tour; some routes include light snacks.
