Magdalen (or sometimes Magdalene) Island is an island of about 7 acres (3 hectares) in the Hudson River in Dutchess County across from Glasco and near Tivoli and Saugerties. It is not currently inhabited and there are no structures on the island. It has been inhabited in the distant past. Rock shelters and a shell midden (heap of discarded shells) left behind by Native Americans are present on the island. Doctor Mary Butler excavated on the island in 1940 and many looters dug pits on the island looking for artifacts. The whole island is forested and host to many species of plants and animals.

Access:

There are two landings on the island. One is large and near the south end. It tends to be muddy. There is a smaller rocky landing on the west side of the island. It's best to approach this landing from the south. Both can be spotted by looking for the light green of day lily plants that only grow on the island at these two places. Both are most easy to land and launch from at high tide and become difficult at low tide.

As of the spring of 2019 the canoe launch off Kidd Lane is still officially closed. The steps and slide are in place but there is no floating dock. If you're acrobatic you can get your kayak launched but it's not easy. For more information see the URL(s) below. If I find out the launch has been reopened I'll post a journal about it here.

https://www.hrnerr.org/tivoli-bays-closure-2017.html

The launch off the North Bay Trail that's marked on the trail map is unimproved, muddy, and there is a dropoff just off shore. It's also a long haul to carry and the marsh offshore is a maze.

More information and regulations:
https://www.dec.ny.gov/lands/92370.html

Other Launches:

Broadway/Diana Street in Tivoli
Canoes and kayaks can be launched from the bottom of Broadway in the town of Tivoli. Cross the railroad tracks only at the crossing gates! The shore is rocky and unimproved. From there it's an easy paddle along the shore south to the island and northernmost trestle into the North Bay. Watch out for protruding rocks near the Sycamore Point portal (the big cement thing with a door in it).

Glasco Mini-Park
Across the river is Glasco Mini-Park. It's a beautiful little park with a cartop ramp near the entrance and two back-in ramps for putting in power boats and jet skis. Be careful on the cartop ramp. It is steep and the cement is smooth. It gets very slippery at low tide. From there it's possible to cross the river carefully. The distance to the island is about two thirds of a mile. Please do not attempt this if you are an inexperienced boater or kayaker or in bad weather or in a small consumer kayak. There is a large shallow known as Saddlebags just south of Glasco. It's not a problem for a canoe or kayak but can be as shallow as five feet at low tide. The deep channel used by large ships and barges is directly across the river and passes very close to the island. The western edge of the channel is marked to the north and south by green buoys with the numbers 89 and 87 (87 has an AIS transmitter). Watch out for large ships and barges. They can be moving faster than they look like they are. The same applies to large powerboats. Either type of craft can create a large wake.

Sojourner Truth Ulster Landing Park
It's easy to launch from the beach at this larger park that's also on the opposite side of the river. The total distance to the island is about four miles. I'd recommend crossing the river wherever it's safe and following the shoreline of Cruger Island then heading straight to Magdalen. Remember the way the tide is moving. Fighting the tide can make for a long unpleasant day. South Cruger island is along the way and also very interesting. There are the ruins of a 'Mayan' temple on the island that was built by the Cruger family and was once stocked with real Mayan artifacts. The ruins of the Cruger house are also visible on the peninsula. The park is a very pleasant place to launch from if you don't mind a bit of planning and some paddling that can be challenging. Watch out for large bricks and friendly dogs on the beach. Despite what some sites on the internet say there is no fee to use this park.

Tides at Tivoli:
https://tidesandcurrents.noaa.gov/noaatidepredictions.html?id=8518964

There is a free NOAA chart of the area available from the Map Store on the Avenza Maps app.
The map you want is: HUDSON RIVER-WAPPINGER CREEK TO HUDSON-RIGHT PANEL

There is a great book about the bays by Esther Kiviat.
http://www.catskill.net/purple/tivoli.htm