Depending on the season and the water level of the river, either a rubber boat or a wooden raft will be used. On the banks of the Alas river, in Muarastulen, the boat or raft will be prepared for the trip. All passengers will get a live jacket to wear and you will receive detailed instructions from your guide. Both guide and passengers will take their seats and soon after, you will find yourself wrapped up in the rapid flow of the Alas river.
This river runs past majestic trees, overgrown with climbing plants, which together make up an impenetrable wall of vegetation. On the banks, you will be able to enjoy the sight of monkeys swaying through the trees as well as a variety of beautiful birds. The river has its quiet moments, but sometimes the guide will have to make every effort to keep the boat in its course. Passengers can choose to assist the guide or simply relax and enjoy the scenery. The reflection of the sun in the water can cause heavy sun burn, so please be sure to bring a hat and a protective sun cream.
On the last day of the trip, the boat will cruise the lower reaches of the river, towed by an old river boat. The trip ends in Gelambang. From there the individual passengers can choose to continue their trip, by small buses, in the direction of Berastagi, Lake Toba, Singkil or other places.