Dolphin Swim in Japan: Mikurajima vs Toshima

Quick answer

Choose Mikurajima if your priority is the classic dolphin swim destination, a larger dolphin population, and the best chance of repeated encounters. Choose Toshima if you want a smaller-island trip where lodging may be easier to arrange and many swimmers report close-feeling encounters with slightly larger-looking individuals.

Neither island is logistically easy. Both are vulnerable to wind and sea conditions because each has a small island port. You should plan with extra time, book accommodation early, and avoid treating either trip as a casual day outing.

• Mikurajima: more dolphins, famous destination, baby encounters are a realistic hope in season
• Toshima: fewer dolphins, but some swimmers describe a close-feeling distance and larger-looking individuals
• Both: landing can be difficult when wind and swell are wrong
• Both: no camping or sleeping rough; arrange lodging before you go
• Backup option: Mikurajima can also be done as a dolphin trip from Miyakejima

First: what are the three trip types?

When people compare Mikurajima and Toshima, they are often mixing three different travel patterns. The first is a Mikurajima-stay trip: you take the overnight ferry to Mikurajima, stay on the island, and join a local dolphin swim boat around Mikurajima. This is the classic version.

The second is a Miyakejima-based Mikurajima trip. You stay on Miyakejima, then a local operator takes you by boat to the waters around Mikurajima. This can reduce the risk of being unable to land on Mikurajima itself, but it adds a longer boat transfer before and after the swim.

The third is a Toshima-stay trip. You take the ferry to Toshima, stay on the island, and join a local dolphin swim boat around Toshima. It is not a side version of Mikurajima; it is a separate island trip with its own ferry route, lodging situation, boats, and dolphin population.

• Mikurajima stay: the iconic route, but ferry landing risk is central
• Miyakejima base: a backup-style route to Mikurajima waters with longer boat time
• Toshima stay: a separate island option, usually simpler once bookings are secured
• This article compares all three, because the best choice depends on schedule flexibility as much as dolphin numbers

The biggest difference: population and predictability

Mikurajima is the more famous dolphin swim island because the dolphin population around the island is larger and encounters are considered highly likely when sea conditions allow boats to reach the area. Operators still avoid guarantees because dolphins are wild animals and the sea can change quickly.

Toshima has a smaller resident dolphin group. The island village page describes around 20 dolphins in the surrounding sea. That smaller number means the dolphins may be away from the usual area at times, but many trip reports and operators describe Toshima dolphins as curious and sometimes very close-feeling when the timing is good.

Landing risk and access

Both islands are exposed to the sea. If wind or swell hits the wrong direction, the ferry may not land. This is one of the main reasons dolphin swim trips in the Izu Islands require more schedule flexibility than a normal city tour.

Mikurajima has a particularly strong reputation for difficult landings. Some travelers choose a Miyakejima-based trip instead: Miyakejima has larger port options and can be a more stable base, then operators travel by fishing boat to the waters near Mikurajima. The tradeoff is boat time: the Miyakejima route involves roughly 40 to 50 minutes each way to the dolphin area.

• Mikurajima stay: shorter dolphin boat ride once on island, but ferry landing risk is a major concern
• Miyakejima base: usually safer for reaching the base island, but longer boat ride to the dolphin area
• Toshima stay: also exposed to landing risk, but often feels simpler once accommodation and operator are secured

Tokyo-side access: Takeshiba and Tokai Kisen

For most travelers, the route starts in central Tokyo. Go to Takeshiba Pier, usually by walking from Hamamatsucho Station or using Takeshiba Station on the Yurikamome line, then board a Tokai Kisen ferry.

Toshima and Mikurajima are not on the same overnight ship route. Toshima is on the Oshima-Toshima-Niijima-Shikinejima-Kozushima route, served by the Salvia-Maru large passenger ship and, depending on date, jet ferry services. Mikurajima is on the Miyakejima-Mikurajima-Hachijojima route, served by the Tachibana-Maru large passenger ship.

This route difference matters when you compare risk. Toshima belongs to the Kozushima-side island chain route. Mikurajima belongs to the Hachijojima-side route, and a Miyakejima-based dolphin trip uses Miyakejima as the more stable base before heading to Mikurajima waters by local boat.

The usual large-ship pattern is overnight outbound and daytime return. As a timetable example, the Toshima route can leave Tokyo around 22:00 and reach Toshima early the next morning, around 7:40. The return can leave Toshima around midday and reach Tokyo in the evening. The Mikurajima route can leave Tokyo around 22:30 and reach Mikurajima around 6:00, with the return leaving Mikurajima around lunchtime and reaching Tokyo in the evening. Always check the exact seasonal timetable before booking.

Cabin choice matters more than many first-time visitors expect. Standard 2nd-class Japanese-style rooms are shared floor-sleeping spaces rather than beds, and onboard blankets are rented for a small fee; Tokai Kisen announced a blanket rental price revision to 200 yen from November 2025. Higher classes may add bunk beds, bedding, or private-room comfort depending on ship and room type. Because the outbound leg is a night ferry followed by an early arrival, do not assume you will get a full, hotel-like night's sleep before swimming.

• Tokyo access: Hamamatsucho or Takeshiba Station to Takeshiba Pier
• Toshima: Tokai Kisen route toward Kozushima, usually associated with Salvia-Maru
• Mikurajima: Tokai Kisen route toward Hachijojima, usually associated with Tachibana-Maru
• Typical rhythm: night departure from Tokyo, early morning island arrival, midday island departure, evening return to Tokyo
• 2nd-class rooms can mean shared floor sleeping; upgrade if sleep quality matters
• Always check the latest timetable and operation status on Tokai Kisen before departure

Boats and entry style

Mikurajima island boats are often small fishing boats. The upside is maneuverability: a small boat can turn and position efficiently around dolphins under the captain's judgment. The downside is comfort and entry style, which can feel rough or compact depending on the boat and sea state.

Miyakejima-based Mikurajima trips may use larger fishing boats. This can feel more stable during the crossing, but some swimmers find entry and exit harder, especially with long fins or crowded timing. Long fins can be damaged if they are handled carelessly around ladders, rails, or other swimmers.

Toshima boats are often described by swimmers as relatively easy to enter from. This is one reason Toshima can feel friendly for people who are nervous about the first entry, although sea conditions and operator setup still matter more than the island name.

Accommodation and booking

Accommodation is part of the dolphin swim plan, not an afterthought. Mikurajima has limited lodging, and several sources note that overnight stay planning is essential. Toshima also prohibits camping and sleeping rough, but lodging may be somewhat easier to secure than Mikurajima depending on date and operator.

For both islands, book early. Operators are limited, accommodation is limited, and busy weekends or holiday periods can fill quickly. Do not arrive without lodging. This is not the kind of island trip where you can improvise a tent or sleep near the port.

• Mikurajima: book lodging and dolphin swim early; expect limited rooms and shared-room conditions in some tours
• Toshima: some operators/inns can arrange lodging and dolphin swim together
• Both: no camping or sleeping rough
• Both: confirm ferry, lodging, operator, payment, and cancellation rules before departure

Rules and ethics

Dolphin swims are different from whale swims: duck diving may be allowed, depending on local rules and guide instructions. Still, the basic ethics are strict. Do not touch dolphins, chase them, feed them, use flash, use lights, use underwater scooters, or force an interaction.

A good dolphin swim is not about getting the closest possible video. It is about entering quietly, reading the animals, leaving when they show disinterest, and following the captain and guide. Toshima rule pages explicitly warn against chasing, touching, feeding, flash, noisy equipment, and unsafe positioning under the boat.

Which should you choose?

For a first Japan dolphin swim, Mikurajima is the iconic choice if you can secure lodging and accept ferry uncertainty. Toshima is a very strong alternative if you want a smaller, quieter island and a potentially easier lodging/boat setup. If schedule reliability matters most, consider a Miyakejima-based Mikurajima trip, while accepting the longer boat transfer.

The best choice is not simply the island with more dolphins. It is the island that fits your schedule flexibility, swimming confidence, accommodation tolerance, and comfort with small boats.