How much to tip a boat driver in Negombo.

If you negotiated a fair flat rate for the boat tour beforehand tipping is completely optional but always highly appreciated by the hardworking local captains. If the captain was incredibly friendly pointed out specific wildlife in the mangroves and gave you a great smooth ride handing them an extra 500 to 1000 Sri Lankan Rupees roughly 2 to 3 USD at the end of the trip is a very generous and perfect gesture.