It could be 45', but Idk why anyone would report their boat as being larger than it actually is when it comes to paying moorage fees. Though maybe it's 45' LOD and it's 48' with the anchor and swim platform.
At any rate, I was just reading Voyaging Under Power and came across the section about Stephen Seaton. I'm wondering if it's perhaps one of his designs.
Both of these are designs of his:
2013 Seaton Trawler Long Range Custom 56 Power Boat For Sale -