105
Sea days logged, 16 November 2025 to 1 May 2026 — the full season, not a sample of the good weeks.
Best time to go
The best time to swim with sperm whales
Short version: any week of our season. Dominica’s sperm whales are resident, not migratory — there is no window to hit and no month to miss. We run November to May.
Nov – May
Our season. Closed June to the end of October for hurricane season
200+
Resident sperm whales off this coast, here all year
75%
Of logged sea days last season found sperm whales
Dec – Apr
When mature males travel in to mate with the resident females
The short answer
There is no peak week.
Most whale trips in the world are built around a migration. You go to Tonga in August because that is when the humpbacks are there, and in May there is nothing to see. Dominica does not work like that.
An estimated 200 to 300 sperm whales live off this coast permanently — the same matrilineal families, on the same stretch of water, season after season. They are not passing through on their way somewhere else, so there is no arrival date and no departure date to plan around.
What that means in practice: a week in December and a week in April give you the same shot. We publish the whole season log precisely so you can check that for yourself rather than take our word for it.
Month by month
What actually changes through the season
Not much — but here is what does.
- November
- The season opens mid-month, once hurricane season is properly done. Last season our first logged sea day was 16 November.
- December – April
- Mature males travel down from colder water specifically to mate with the resident females. They are substantially larger than the animals you will usually be swimming with, so if seeing a big bull matters to you, these are your months.
- May
- The season closes at the start of the month. Last season our final logged sea day was 1 May.
- June – October
- Closed. This is hurricane season in the eastern Caribbean and the sea conditions are not workable for this kind of trip.
The females and young are here the whole time. The mother-and-calf units that most encounters are with do not leave, in any month of our season. The males are the seasonal part.
2025/26 season log
What last season actually looked like
We log the whales sighted and a swim rating for every day the boat goes out, and we publish the whole thing — the record weeks and the quiet ones together.
75%
Of those days we found sperm whales. Across a six-day trip that works out at four to five days with whales.
49%
Rated 8 out of 10 or better by the captain — close, unhurried encounters rather than a glimpse at distance.
What to watch instead
The calendar is not what moves the odds
Three things genuinely affect a week. None of them is the month you picked.
Other predators
Orca and pilot whales
If killer whales or pilot whales move through the channel, the sperm whales clear out and can stay gone for three or four days. It is the one thing no crew and no permit can work around, and it can happen in any month.
Conditions
Swell and distance
Encounters can be up to ten miles offshore, where it may be glass or may have swell. You should be ready to swim to approach and follow an animal that is not waiting for you.
Length of stay
How many sea days you book
This is the one you control. Six sea days is the number that turns a good run of luck into a near-certainty — one or two blank days across a week is the normal shape of a good trip, not a bad one.
Pick the week that suits you
Any of them works. The 2027 dates and prices are online — see which weeks are still open and book from there.