The pond has several potentially hazardous areas for boaters. There is a sand bar that connects Nelson Island to the mainland that varies from about three feet to only inches deep, and is sometimes fully exposed in the mid to late summer. Because of the pond's shallow depth (on average around nine feet), many large rocks pose serious threats. Not all of these rocks are clearly marked, but most are.

The largest of these rocks is known as Acre Rock because of its approximate size. It is flat on its top, lies close to the surface and sits midway between the east and west shores of the pond approximately 1/4 mile north of Hemlock Point at Long Pond's southern end. Acre Rock sits approximately at the town line separating Lakeville and Freetown.

For a boater inexperienced navigating Long Pond, it is always advisable to remain on the western side of the islands when traveling north or south to avoid the many rocks and sandbars that exist. Also when passing Nelson Island going north or south, always do so in the middle of the channel between the island and shoreline, due to a string of several rocks running north and south off the island's western tip. When entering the lake's southwestern area, to the west of Hemlock Point, avoid the middle of the entrance due to several rocks that are not always marked.