Willem de Vreng
| Date | Swim | Route | Km | Age | Time/Place |
|---|---|---|---|---|---|
| 1962 Jul 15 | Maratona del Golfo Capri-Napoli ILDSF |
Capri to Napoli | 36 | 08:35:25 (5/19) | |
| 1963 Feb 10 | Maratón Acuatíco Río Coronda | Santa Fe to Coronda | 63 | 09:03:10 (2/18) | |
| 1963 Jul 14 | Maratona del Golfo Capri-Napoli ILDSF |
Capri to Napoli | 36 | 09:05:12 (4/24) | |
| 1964 Jul 12 | Maratona del Golfo Capri-Napoli ILDSF |
Capri to Napoli | 36 | 12:33:02 (6/17) | |
| 1965 Jul 11 | Maratona del Golfo Capri-Napoli ILDSF |
Capri to Napoli | 36 | 10:41:56 (7/18) | |
| 1970 Jun 27 | WPMSF (Utrecht) | Maarsseveen Plassen buoy course | 20 | 06:54:01 (9/16) |