With a good guide and a small boat, you can see lots of different animals and birds in their natural environment, including herons, sloths, monkeys, iguanas, and caymen. Wonderful way to spend an hour or two.

My family (husband and 8-year old daughter) and I visited Costa Rica for the first time in October of 2012. One of the best part of our trip was taking a boat ride from the Moin port (near Limon) along the canals towards Tortuguero on "Riverboat francesca". This is a nice small boat operation run by Modesto and his wife (from Michigan) Francesca that takes tourists along the beautiful canals of Costa Rica.
Mr. Modesto is really an awsome guy who has been doing this for over 20 years (thats what he said) and seems to be extremely knowledgeable about the entire river front and can so quickly spot birds, monkeys, crocodiles even at varying speeds on the boat. because it was the lean season (green season) it was just us three on the boat with Modesto, which made it like a private tour without te cost of paying for one. He is a kind gentleman who spotted birds, crocodiles etc. and made my daughter so happy.
We didn't get to meet Ms. Francesca, but I need to thank her very much because she influenced Modesto to take us on this boat ride even with no other passengers to make it worth his while. This lovely couple live in San Jose, which is about 3 hours from Moin port; so for him to drive all the way to come to Moin and take us on this trip was special.
Anyway, if any one wants to experience a nice boat ride along the nice thick jungle of Costa Rica, you should take this canal ride to Tortuguero from Moin on Riverboat Francesca.

Thanks
Sheryl

The bulk of sighting is by boat. We were in an open, motorized boat. Some guides use canoes. I think this would be less intrusive.
Unfotunately when it pours rain as it did during our day of sightseeing, the animals are under shelter and not seen. We did see many birds, insects and amphibians.
The guide was well informed and concerned that we were sightseeing in a downpour, but there was nothing to be done.

Our canal tour was great. Very quiet in the afternoon and our guide was stupendous. He could find the tinies of animals from 20 feet away! Our favorites were the slothes but the birds were gorgeous and we even saw a few cayman aligators. Loved it.