| U-Boys | 77 | 1104089 | 144144 | U Boys Inc Llc | B2 |
| Ultra Seahorse | 35 | 913311 | 138241 | Francoeur, Ronald A | B1 |
| Unchained | 26 | MS3677BN | 180674 | Peters, Noah J | B1 |
| Uncle Johnny | 23 | MS2278AX | 164078 | Amaral, Peter M | B1 |
| Uncle Steamer | 12 | MS1046BV | 185516 | Rogers, Benjamin J | SR |
| Uncloudy Day | 25 | MS2350BC | 139565 | Moss, Robert S | B1 |
| Unconditional | 42 | 1347230 | 187374 | Unconditional Llc (, ) | B1 |
| Under Dog | 25 | MS8890BT | 184640 | Penta, Guy P | B1 |
| Under Pressure | 22 | MS2719BH | 145590 | Iovanna, David J | B1 |
| Under Wing | 46 | 1207861 | 178038 | Krzyzewski, Peter M | B1 |
| Under Wing | 46 | 1207861 | 3806 | Krzyzewski, Peter M | CL |
| Unforgiven | 26 | NH2656LE | 171216 | Willette, Rodney E Jr. | B1 |
| Ungrounded | 27 | NH2625XM | 186693 | Caramanica Electrical Services Llc (Caramanica, Michael A) | B1 |
| Unicorn | 36 | MS7350BK | 5527 | Crabby Apple Fishing Llc (Vona, Mark D) | CL |
| Unicorn | 40 | 626072 | 3124 | Eldridge, Robert J Jr. | ON |
| United States | 76 | 618882 | 73816 | Boat United States, Inc (Lourenco, Felicio) | OL |
| Unleased | 28 | MS8273BV | 186457 | Rheaume, Kenny S | B1 |
| Unnamed | 20 | MS2321BJ | 175261 | Doung, Sovann Sd | B1 |
| Unnamed (Lane) | 16 | MS9867BA | 169953 | Lane, Edward H Sr. | SS |
| Unorganized | 30 | 1297371 | 151769 | Decosta, Gary | B1 |
| Unreel | 26 | MS8704BP | 185090 | Corsetti, Timothy J | B1 |
| Unreel | 27 | MS6479BS | 186604 | Unreel Sportfishing (Blake, Christopher M) | B1 |
| Unreel | 20 | MS1488BS | 185753 | Silveira, George M Jr. | B1 |
| Unstructured | 36 | 1187752 | 177838 | Shramek, Adam D | B1 |
| Uptown Girl | 34 | 982983 | 92744 | Siboc Clam Partnership (Pickard, Stephen D) | CL |