PEI
PEI - Prince Edward Island
They all have water borders of one kind or another but Alberta and Saskatchewan had their borders drawn from Ottawa without deliberately using rivers, lakes or shorelines for borders. Some of Alberta's border with BC is along the Continental Divide and I would consider that a water border, in a sense. So the safest answer is Saskatchewan.
plains not water
Three sides of water
The provinces entirely surrounded by salt water in Canada are Newfoundland and Labrador, specifically the island of Newfoundland. Additionally, the province of Prince Edward Island is also entirely surrounded by salt water. These regions are characterized by their maritime geography and coastal ecosystems.
PEI
Hawaii is entirely surrounded by water. In terms of percentage of border surrounded by water it would be Hawaii. If you're measuring the total length of the coastline, it would be Alaska.
An island is a piece of land entirely surrounded by water.
Europe, Asia, North America, South America, and Africa are not completely surrounded by water (Although if counting the Panama Canal and the Suez Canal, then North America, South America, and Africa would be completely surrounded by water).
Quebec and New Brunswick ==================== The Chignecto Isthmus, which connects New Brunswick and Nova Scotia, is only 24 miles across.
Asia/Europe, as they are connected? so they are not Entirely surrounded.
An area almost entirely surrounded by water is called a peninsula.
Canada has one province that is primarily a peninsula: Nova Scotia. This province is almost entirely surrounded by water, with the Atlantic Ocean on three sides. Additionally, parts of other provinces, such as New Brunswick and British Columbia, have peninsular characteristics, but they are not entirely peninsulas like Nova Scotia.
All except for Alberta and Saskacthewan all border water.
PEI - Prince Edward Island
A peninsula is a piece of land that is almost entirely surrounded by water. An antonym for peninsula would be bay, as a bay is a body of water that is almost entirely surrounded by land.