Here's a (top secret) blueprint of the Unknown Artefact leaked from an intercepted Federation communique. Larger edition here
So how does the Dolphin fit? Well it's size gives it a volume of 9,481.5m3, so it is between the Adder and Cobra Mk 3 on a small landing pad.
After threatening to get it done, here it is at last! in 1080p and 4k