First Lake is a small lake — more accurately described as a large pond — located in New Brunswick, Canada, forming part of the Diggity Stream system. It sits downstream of Wauklahegan Lake, connected to it via an outlet channel that, under high-water conditions, can run as a fast, rock-sparse rapid stretching approximately 300 metres. Paddlers arriving from Wauklahegan Lake will encounter a rock dam at the outlet; during periods of elevated water, this dam may be fully submerged with water flowing over its entire length and through adjacent woodland, effectively creating a runnable rapid rather than a portage situation.

At the far end of First Lake, Route 630 crosses the Diggity Stream on a bridge. This bridge represents a notable hazard: clearance beneath it varies significantly with water levels, and during high-water periods it can drop to less than two feet, requiring paddlers to lie flat in their craft to pass through. Paddlers should assess water levels carefully before committing to this passage, particularly following heavy rainfall.

First Lake is typically encountered as a transit segment within a longer multi-day canoe route through the Chiputneticook Lakes region, which straddles the Maine/New Brunswick border and drains into the St. Croix River. Wind can be a factor even on this small water body, and paddlers should be prepared for headwinds when crossing open water.