Here is my 1:72 scale model of a really large late-viking-era warship. 

The model is loosely based on the Haithabu, Roskilde and Skuldelev ships.  It is a 64-seater, extremely narrow and shallow, and very long.  I believe that the crew were not supposed to move about very much on such ships during a trip and also I do not see how they could have taken a lot with them, other than their personal gear.  Apparently, there was a rule that such ships had to be at least ¾ crewed up before they could put out, likely for safety reasons.

In the pictures you can see my result.  It required a huge number of painted and mounted shields and a few metres of thread for the rigging. The crew on the oars also took a while to print and paint.  The end result is half a metre long, so do check ahead of time where you have enough shelf space to accommodate such a wonder.

Next you will need to book around one week of production capacity on your printer:  the hull comes in four parts, each of which will print out in ca 12-13 hours (0.15mm layers, 0.4mm nozzle, PLA).  I am attaching some work-in-progress pictures.  In some pictures, a finished model of the smaller 26-seater ship is put alongside to convey an idea of the dimensions of this larger ship.

My thanks here go to my very indulgent wife, and to my cats who have provisionally agreed not to adjust the model at this stage (for now).

Update 28.06.2020: added a "smallscale" version at 50% of original size (1:144 scale) with reinforced hull and all in one piece.  This can now be scaled down further for printing out for 6mm figures (1:320, use 45% size) on a FDM printer. I tested this size using 0.06mm layers and 0.25mm nozzle and it came out OK.  All parts have been combined here (hull A+B+C+D+rudder+benches+anchor, but no masts, shields, oars or prow decorations).

Update 15.08.2021: Overhauled the hull to eliminate angular effects on the strakes.  Also, based on feedback, I have re-sized the hull to make it slightly (5%) larger than before (it now comes to 52 cm in length when assembled).  This should make adding the shield racks and inserting the shields less difficult than it was before.

Update 30.08.2021: Corrected the shape of the keel profile for the two ends (parts A and B) - this needed to be flatter and then more rounded out at the front and back ends of the ship.  Also checked+adjusted thickness of all the hull planks (strakes) to ensure proper printing out of all four hull parts at 50% size under normal FDM printer settings.