| O'Henry | 20 | MS2005DB | 140781 | Berube, David A. | B1 |
| Obadiah | 26 | 912088 | 120603 | Page, Stephen G. | B1 |
| Ocean Boy | 74 | 544841 | 155439 | Ocean Boy, Inc | B2 |
| Ocean Cat | 76 | 514627 | 163245 | New Ocean Llc | B2 |
| Ocean Fox | 77 | 1033251 | 163242 | New Ocean Llc | B2 |
| Ocean Gold | 78 | 1037847 | 150185 | Ocean Gold Inc | ON |
| Ocean Hunter | 88 | 614436 | 163246 | New Ocean Llc | B2 |
| Ocean Hunter | 34 | 905607 | 139461 | Francis, Aaron M. | B1 |
| Ocean Hunter | 45 | 675834 | 1149 | Mello, Kevin M. | CL |
| Ocean Lady | 75 | 611992 | 149595 | Ocean Fishing Llc | B2 |
| Ocean Leader | 84 | 617297 | 163247 | New Ocean Llc | B2 |
| Ocean Life | 34 | 1107832 | 2680 | Woollam, Gordon F. | CL |
| Ocean Mogul | 34 | 1188775 | 139058 | Mogul, John D. | B1 |
| Ocean Pride | 79 | 973175 | 155209 | Ocean Pride, Inc. | ON |
| Ocean Princess | 81 | 916992 | 150182 | Ocean Princess Inc | ON |
| Ocean Prowler | 77 | 594025 | 163248 | New Ocean Llc | B2 |
| Ocean Prowler | 84 | 1120035 | 150189 | Ocean Prowler Inc | ON |
| Ocean Pursuit | 73 | 608631 | 163244 | New Ocean Llc | B2 |
| Ocean Rancher | 44 | 595889 | 69166 | Ingham, Bruce W. | OL |
| Ocean Runner | 36 | 1183183 | 143672 | Flannery, Richard C. | B1 |
| Ocean Scout | 20 | MS9531KS | 6974 | Eliopoulos, Michael G. | CL |
| Ocean Scout | 19 | MS7503HT | 161646 | Picard, Dennis P. | SR |
| Ocean Spray | 38 | 541496 | 3597 | Cole, Howard A. | CL |
| Ocean Wave | 68 | 280172 | 160791 | Ocean Wave Scallop Co Inc | ON |
| October Sky Iii | 20 | MS5392KK | 4278 | Medico, Robert J. | CL |
| Odessa | 40 | 554354 | 149313 | Barrett, Timothy A. | B1 |
| Odin | 25 | MS3479KR | 1735 | Thomas, Baird M. | CL |
| Odysea | 31 | 928787 | 139537 | Wilkins, Ralph J. | B1 |
| Odyssey | 27 | MS7690BA | 166733 | Holmes, Thomas C. | B1 |
| Odyssey | 22 | MS9219HY | 17198 | Pickering, Robert P. | B1 |
| Odyssey | 25 | MS5736HT | 162519 | Carlson, Mark | B1 |
| Odyssey | 27 | MS5051LL | 62671 | Long, Leon E. | B1 |
| Off Duty | 22 | MS1199AD | 142376 | Dunn, Joseph A. | RR |
| Offshore | 19 | MS6564AY | 162490 | Phan, Chinh | B1 |
| Offshore Account | 25 | MS8673AY | 162967 | Cuticchia, Adam E. | B1 |
| Offshore Whore | 24 | RI0257V | 166292 | Pimentel, Charles K. | B1 |
| Offshorefever | 32 | FL3122PF | 166406 | Britton, Jana | B1 |
| Often Annie | 20 | MS0001L | 164074 | Estabrook, Lorne D. | B1 |
| Oh Baby | 34 | 595084 | 7061 | Stiles, Leslie H. | CL |
| Oh Susana | 19 | MS3881AV | 166154 | Brum, Steven | B1 |
| Ol Salt | 24 | MS3281KW | 60573 | Teller, Thomas A. | RR |
| Ol Yella | 20 | MS5115HC | 163994 | Ingle, Harry C. | RR |
| Old Coot | 27 | 1214418 | 164648 | Borden, Charles R. | OL |
| Old Dog | 34 | MS1373AR | 126173 | Britt, Joseph S. | B1 |
| Old Dog Ii | 25 | MS6279AR | 100251 | Eldridge, Thomas L. | B1 |
| Old Glory | 24 | MS9694AF | 147 | Foote, David F. | CL |
| Old Glory | 42 | 1210671 | 3735 | Piper Jr., David G. | CL |
| Old Squaw | 27 | 903934 | 4755 | Cullum, Andrew S. | CL |
| Old Squaw | 35 | 683088 | 2825 | Borges, Jay B. | CL |
| Old Squaw | 18 | MS2884AT | 100503 | Chartier, Paul C. | B1 |
| Oldsquaw | 17 | MS9308AT | 158535 | Perkins, Blair C. | B1 |
| Ole Yeller | 15 | MS7663AH | 142362 | Ashton, Gayle J. | IN |
| Olivia & Rafaela | 71 | 553777 | 153495 | Olivia & Rafaela Fishing Llc | ON |
| Olivia Catherine | 72 | 533196 | 158402 | Reposa, Peter A. | ON |
| Olivia Madison | 37 | 661445 | 137870 | Mello Sr., Michael A. | CL |
| Olympia | 83 | 684132 | 126465 | Salmon Falls Trawler, Inc. | ON |
| Omega | 24 | MS0009MG | 166412 | Grabowski, Mark D. | B1 |
| On Again | 24 | MS8707ZB | 150518 | Olival, Thomas | B1 |
| On The Edge | 26 | MS9665AT | 155819 | Freeman, David W. | RR |
| On The Fly | 24 | MS0063RS | 139286 | Sigler, James R. | B1 |
| On The Pile | 17 | MS2553AN | 151512 | Avellar, Chad J. | B1 |
| On The Pile | 17 | MS2553AN | 166382 | Avellar, Chad J. | RR |
| On Time | 31 | MS3459KN | 94191 | Koutalakis, Demetrios M. | B1 |
| One Bad Larry | 23 | MS3705AL | 157716 | Brown, Laurence A. | B1 |
| One Eyed Jack | 15 | MS5047AS | 166601 | Mchugh, William J. | SL |
| One Particular | 20 | MS5919KM | 101962 | Baker Jr., Kenneth W. | B1 |
| Optimism | 23 | MS0777MN | 164083 | Netto, Michael J. | RR |
| Opus Iv | 24 | MS5572BA | 165886 | Noll, Edmund P. | B1 |
| Orion | 82 | 611248 | 163993 | Princess Diana 1 Inc | ON |
| Orion | 26 | 638987 | 74302 | Rindfleisch, Edward F. | B1 |
| Orion | 38 | 949186 | 162661 | Boreland, Josef | B1 |
| Osprey | 40 | MS2568KN | 16651 | Smith, Robert F. | CL |
| Osprey | 108 | 683328 | 120027 | Irish Venture, Inc. | OL |
| Osprey | 26 | MS0041JB | 64536 | Bondorew, John | B1 |
| Osprey | 35 | 932787 | 93804 | Corbett Jr., Stephen L. | B1 |
| Otter Ii | 20 | | 2678 | Medeiros, Michael G. | B1 |
| Ouija | 23 | MS7130BA | 138930 | Miszkin, Gerald S. | B1 |
| Our Island | 38 | 1173303 | 140257 | Besch, Rachel L. | B1 |
| Our Leon | 19 | MS6884AM | 164126 | Berns, Jordan C. | IN |
| Our Tern | 21 | MS4455BA | 160800 | Chambers, David L. | RR |
| Out Cast | 31 | 1200610 | 164205 | Lambert, John S. | B1 |
| Out N About | 15 | MS0160CC | 160993 | Chabot, Stephen M. | RR |
| Out Of Bound | 26 | MS5014KM | 104003 | Chisholm, Philip A. | B1 |
| Outer Limits Ii | 36 | 1171376 | 162645 | Duggan Jr., Frank J. | B1 |
| Outer Marker | 36 | 637853 | 4922 | Mccarthy, Sean P. | CL |
| Outrage | 19 | MS4388AM | 150142 | Mak, Heang | B1 |
| Outrage | 24 | MS4820JA | 156213 | Auld, James J. | B1 |
| Outrageous | 21 | MS5630AH | 146583 | Sanclemente, Charles G. | B1 |
| Overtime | 35 | MS2249BB | 1003 | Mahoney, Dennis | CL |
| Overtime | 26 | MS0620MB | 158726 | Balboni, Matthew P. | B1 |