Hotels near the Amsterdam wharf

There's an Ibis hotel (part of the Accor chain) next to the train station by the wharf that may fit what you are looking for. I've stayed there and it was clean, not too expensive, and in an easy location. You can see the ships from the hotel so it's pretty close.

I have also stayed at the Ibis recommended above. It’s a very convenient location but be aware that Viking leaves from different locations depending pier availability. I think I remember someone saying the specific docking location isn’t assigned until the day before.

Other than the brief convenience of being near the boarding dock for the ship, is there a reason you WANT to be near the wharf area?

The Amsterdam "core" is fairly small so there isn't really a huge advantage to picking a hotel by the dock vs any of the REALLY wonderful hotels scattered throughout the rest of the city.
I'd recommend thinking about choosing a hotel that puts you within easy walking distance of the many great museums and restaurants and parks of the city. It might mean you spend a little longer on getting to the ship, but I think that time is a fair trade.

When we did our viking cruise from Amsterdam, we stayed at the Doubletree hotel. The dock was a short walk to where the Viking Ships docked, so we were able to wheel our bags over. Good thing too, as it was Kings Day and all public transportation not running and cars and taxis were not permitted in the city center on that day. Several couples who stayed at accommodations in the Musuemplein area, ended up walking the long distance to the ship. Boy, were they unhappy and complained about it at dinner abroad ship.
The Double tree is a short walk from Amsterdam Centraal Station, so there was no problem taking the trams to visit the museums and/or walking to sites in the Jordaan, or the Red Light District, etc.