Mosquito Bay
Vieques bio bay moon calendar for 2026
Use the new moon as your planning anchor. The seven-night windows below cover the three nights before and after it.
Less moonlight gives the glow more contrast. Cloud cover, water conditions, and moonrise time still shape a single night; operators decide whether a tour runs.
The next window, night by night
Sep 7-Sep 13The tables below give each window as one block of seven nights. The nights inside a window are not interchangeable. True dark needs the sun far enough down and the moon under the horizon at the same time, and the moon shifts its rising by about fifty minutes a day. Across this window the darkest night runs 1 h 28 m longer than the shortest.
Pick a night. Bar height is how long the bay stays dark.
Aug 30Nov 17
- Mon 7 7 h 49 m
- Tue 8 8 h 51 m
- Wed 9 9 h 14 m
- Thu 10 9 h 15 m
- Fri 11 9 h 16 m
- Sat 12 9 h 17 m
- Sun 13 8 h 55 m
Sun and moon positions computed for Mosquito Bay at 18.1263, -65.4401 with Astronomy Engine. Dark means the sun below eighteen degrees and the moon below the horizon. Weather is not in the calculation.
2026 darkest-night windows
Vieques local time| Month | Dark-window dates | Exact new moon | Next full moon |
|---|---|---|---|
| January | Jan 15-Jan 21 | ||
| February | Feb 14-Feb 20 | ||
| March | Mar 15-Mar 21 | ||
| April | Apr 14-Apr 20 | ||
| May | May 13-May 19 | ||
| June | Jun 11-Jun 17 | ||
| July | Jul 11-Jul 17 | ||
| August | Aug 9-Aug 15 | ||
| September | Sep 7-Sep 13 | ||
| October | Oct 7-Oct 13 | ||
| November | Nov 6-Nov 12 | ||
| December | Dec 5-Dec 11 |
2027 darkest-night windows
Vieques local time| Month | Dark-window dates | Exact new moon | Next full moon |
|---|---|---|---|
| January | Jan 4-Jan 10 | ||
| February | Feb 3-Feb 9 | ||
| March | Mar 5-Mar 11 | ||
| April | Apr 3-Apr 9 | ||
| May | May 3-May 9 | ||
| June | Jun 1-Jun 7 | ||
| July | Jun 30-Jul 6 | ||
| August | Jul 30-Aug 5 | ||
| August | Aug 28-Sep 3 | ||
| September | Sep 26-Oct 2 | ||
| October | Oct 26-Nov 1 | ||
| November | Nov 24-Nov 30 | ||
| December | Dec 24-Dec 30 |
Book the date before the operator
Hold your darkest available night first, then compare the licensed operators by price, boat type, and departure time. Tours often sell out around holidays and low-moon weekends.
Ferry schedules are published in limited date ranges and can change. Check the official month for your trip and confirm that your tour ends before treating a same-night return as possible.