Some cottagers and companies are feeling more than a little glum around the Great Lakes this spring because of water levels that remain unusually low.

In Georgian Bay, off Lake Huron, for instance, boaters are having trouble navigating safely. Water near Midland, Ont. is down almost a full metre from just a few years ago.

The risk of hitting rocks and sandbars is now so high, some people have spent thousands of dollars installing special electronic equipment on their crafts.

Boat owner Gary Pickering measures the water
Boat owner Gary Pickering measures the water

Towns such as Penetanguishene have been forced to shell out hundreds of thousands of dollars over the past few years to dredge their harbours.

It's not just a concern for recreational boaters. Big shipping companies have also been hurt by the sinking water levels.

Every time the lakes go down a centimetre, the large ships have to lighten their loads before embarking on their next journey. This cuts into their profits, and ends up costing customers more to ship cargo in the long run.

The Great Lakes are at their lowest level in decades. Experts believe part of the problem is that the region is still adjusting after years of unusually dry weather in the 1990s.

While some blame global warming, others think that the rise and fall in lake levels is part of a natural cycle, and that the water fell even further in the 1920s and 1960s.