Specifications m.s. Sier:
| Year of construction | 1995 |
| Length | 73,20 m |
| Width | 15,90 m |
| Maximum draugth | 17,0 dm |
| Engines | 4 x 650 kW |
| Speed | 19 km/h |
| Number of passengers | 1200 |
| Number of passenger cars | 72 |
The other ferry sailing on the line Holwerd - Ameland, is m.s. Oerd.