Gananoque Boat Tours — 1000 Islands Cruises & Boldt Castle

Which 1000 Islands Boat Cruise Should You Choose?

A Gananoque boat tour can be a one-hour taster or the better part of a day, and the right one depends on how much time you have and whether you want to set foot on Boldt Castle. The one-hour cruise loops through the tightest cluster of islands right off Gananoque — the most scenery for the least time. The three-hour narrated cruise ranges wider, past the St. Lawrence Seaway shipping channel, Millionaire's Row and the 1000 Islands International Bridge, all from the deck. The five-hour cruise is the only one that actually lands: a two-hour stopover on Heart Island to walk through Boldt Castle itself. From Ivy Lea, a shorter scenic run takes in both Boldt and Singer castles without a border crossing.

Here's how the main Gananoque boat tours compare at a glance.

The Boldt Castle Cruise — the Story Behind the Stopover

Boldt Castle is the reason many people take a Gananoque boat tour in the first place. In the early 1900s, hotel magnate George C. Boldt — proprietor of New York's Waldorf-Astoria — set out to build a 120-room, six-storey Rhineland castle on Heart Island as a monument to his wife, Louise. When she died suddenly in 1904, Boldt ordered all work stopped and never returned; the castle sat empty for 73 years before the Thousand Islands Bridge Authority began restoring it. Only the five-hour cruise stops here, giving you two hours to walk the grand hall, the tunnels and the gardens at your own pace. Because Heart Island sits in U.S. waters near Alexandria Bay, every passenger on the stopover cruise needs a valid passport (or NEXUS card) — there are no exceptions.

If you'd rather not deal with the border, the scenic cruises glide right past the castle for the photo without ever landing.

What You'll See — Singer Castle, Zavikon & Millionaire's Row

Even the cruises that never land pack the St. Lawrence River's greatest hits into an hour or two. Guides point out Singer Castle on Dark Island, built by the head of the Singer sewing-machine company, and the tiny Zavikon Islands, joined by what tour narrators cheerfully call 'the shortest international bridge in the world.' You'll pass Millionaire's Row, where Gilded Age families summered in rambling island cottages, and watch ocean-going freighters slide through the narrow St.

Lawrence Seaway shipping channel. The 1000 Islands International Bridge arcs overhead, and between the big sights are hundreds of pine-topped granite islands — some barely big enough for a single cottage, others cradling sheltered anchorages like Half Moon Bay, where an open-air church service is held on the water each summer. Most of the Gananoque departures are run by City Cruises on triple-decker sightseeing vessels.

• Boldt Castle on Heart Island — the six-storey Gilded Age landmark
• Singer Castle on Dark Island — a real working castle with secret passages
• Zavikon Islands — the famous 'shortest international bridge'
• Millionaire's Row — grand summer estates on the water
• St. Lawrence Seaway — ocean freighters in the shipping channel
• 1000 Islands International Bridge spanning the river

Best Time of Year for a 1000 Islands Cruise

Gananoque boat tours run daily from May through the end of October — the boats are hauled out for the Canadian winter, so there are no cruises from November to April. Peak season is July and August, when the weather is warmest and the islands are at their greenest, but it's also the busiest stretch, with the Boldt Castle stopover often selling out on weekends. Late June and early September are the sweet spots: warm, settled days with thinner crowds.

May and October cruises are quieter and cooler — bring a jacket, as it's noticeably breezier out on the open river — and early October adds the bonus of fall colour across the islands. Mornings are usually the calmest on the water; afternoons can pick up a light chop when the wind rises. Gananoque is an easy day trip from Kingston to the west and Brockville to the east, so a 1000 Islands sightseeing cruise slots neatly into a wider Ontario road trip.

One thing to note: these are daytime narrated cruises rather than a sunset cruise — the last departures leave in the late afternoon.

• May–October: the full cruise season (no winter sailings)
• July–August: warmest and greenest, but busiest
• Late June & early September: warm days, fewer crowds
• October: cool, quiet, and fall colour on the islands

Do You Need a Passport?

It depends on the cruise. Only the five-hour Boldt Castle stopover actually lands on Heart Island, which is U.S. territory — so every passenger on that cruise must carry a valid passport or NEXUS card, with no exceptions, and travellers from outside Canada and the U.S. may also need a visa and ESTA. Every other Gananoque boat tour stays on the Canadian side or simply cruises past the castle without stopping, so no passport or ID is required.

If you don't have a passport handy, the scenic cruises and the one- and three-hour narrated trips still give you the full sweep of castles and islands from the deck.

• 5-hour Boldt Castle stopover: passport or NEXUS card required — no exceptions
• Non-US/Canadian citizens: passport plus any required visa/ESTA
• All other cruises: no passport or border stop
• Scenic cruises pass Boldt Castle for the photo without landing

What to Bring and What to Expect Onboard

The cruise boats are big, stable, triple-decker vessels with both enclosed and open-air decks, restrooms and an onboard snack bar and coffee shop, so a 1000 Islands boat cruise is an easy, family-friendly trip for all ages and for wheelchair users. Sightlines are best from the open upper deck, but it's always cooler and windier out on the river than on shore — bring a light jacket or windbreaker even on a warm day. Sun reflects hard off the water, so pack sunglasses, a hat and sunscreen, and a small pair of binoculars is worth it for the castles and passing freighters.

On the five-hour castle stopover, wear comfortable shoes for walking the grounds and bring water; food and drink can be bought onboard but outside food is not permitted on some cruises.

• A light jacket or windbreaker — it's breezy on the open deck
• Sunglasses, a hat and sunscreen for the reflected glare
• Binoculars for the castles, freighters and island cottages
• Comfortable walking shoes for the Boldt Castle stopover
• Passport for the 5-hour castle cruise; a camera for everything else