There are tour companies on both sides of the toll bridge just 5 km out side of Orange Walk town.
The trip to Lamani is a fun boat ride through the swamp areas of Orange walk County. It takes little over an our to get there depending highly on the level of water in the river and amount of birds and Crocodiles to see.
Th captain of the boat is usually the guide to and if you are lucky as we where he will be very knowledgeable about the area.
To add on your luck you might see the national bird of Belize the Tucan and experience some black howler monkeys.
Not cheap not expencive the tour can be reccomended.
It ads to it that you can dry Camp right there by the river where the boats go. Free of charge.