Those are the ships that daily serves country people from my home village (Sihotang) to cross the Toba Lake. The journey will take average 15 minutes (25 minutes in the evening) with capacity up to 20 people. Daily it usually take 5-10 people except during the weekly-market-day or if there is party or event held at either side of the land. It costs IDR 4000 for each cross so it is unbelievably cheap. The ship’s owner will usually employ a few country people to manage and drive the ship every day, that’s a good work.
You can find a lot of this type of water transportation in many villages around Toba Lake. A great short journey by ship I tell ya, what a brilliant view from the ship. I usually just stand above the flat ship, not prefer to sit down inside with other passengers.