Simpson Reef

Simpson Reef lies off the northern shore of Cape Arago in Coos County, a short boat run around the point from Charleston Marina. The complex is a series of sea stacks and reefs anchored on Shell Island, the largest emergent feature, and the interpretive Simpson Reef Overlook sits at the end of Cape Arago Highway inside north Cape Arago State Park. Diveable water at the reef is described as mostly shallow, with current less of an issue than on the offshore reefs further out. Access is boat only; the interpretive overlook is for viewing, not for entry.

Shell Island and the surrounding rocks make up the largest marine-mammal haul-out on the Oregon coast, with elephant seals and sea lions the dominant year-round presence, joined by harbor seals, and the rocks are part of the Oregon Islands National Wildlife Refuge nesting complex. The Simpson Reef Overlook was built in 2003 to concentrate visitor access at a single interpretive point above the haul-out.

Reef stone surrounding Shell Island and the adjacent submerged rock make up a rocky reef biome that runs across the whole complex. Scuba is the documented diving use of the water outside the refuge standoff envelope. The practical dive window falls outside the calm summer season, since the calm-water months when the reef is easiest to reach overlap peak pinniped haul-out and seabird nesting on the emergent rocks.

Boat access is from the Charleston Marina six-lane ramp (fee) or the free ramp at the end of Michigan Avenue. The Oregon Islands National Wildlife Refuge Rules and Policies page states a 500-foot standoff advisory for all watercraft near the emergent rocks, with landing on any refuge rock prohibited at all times; secondary summaries additionally describe the standoff envelope as a hard seasonal closure through the breeding season, which is a stricter treatment than the language captured on the live refuge page. In water beyond the standoff envelope, take is enforced under standard Oregon Department of Fish and Wildlife recreational marine rules.