Chisholm Engine Dive Site

The Chisholm Engine Site

Depth Range 120' to 150'

The Chisholm Engine Site is the farthest buoy to the southwest from the lighthouse on the Rock of Ages Shoal

The giant engine and stern of the Henry Chisholm broke away from the hull and sits upright at the bottom of the wall that is the northwest side of the shoal. It is rare to be able to see a historic steam engine from bottom to top without the intervening deck levels that typically obscure parts of the machinery when viewed inside the ship. The Chisholm engine sits like a museum display on the bottom of the hull in 150' of water reaching up to 115' at its top. The added narcosis due to the depth of the dive makes the Chisholm Engine a breath-taking sight. There are three buoys marking shipwrecks on the shoal and the buoy farthest and most southwesterly from the lighthouse marks the Chisholm Engine. The mooring is attached to the top of one of the engine cylinders.

The engine sits on a 70 foot long stern section of the bottom of the hull. The hull broke about where the boiler room would have been. The starboard side of the fantail lies off to the port side of the engine along with many smaller machinery artifacts. A short piece of the port side of the fantail lies under the engine section. The propeller shaft and propeller are still intact and attached to the engine showing the complete power-train of the ship. The giant rudder sits directly above the engine site on the wall in 70' of water. It can be found by swimming from the descent line toward the propeller and directly up the wall to 70' of water, where it and other smaller pieces of timber can be seen.

The depth and narcosis makes this not a dive for the beginner or novice diver. If you stay off the bottom and up around the engine, the dive depth can be maintained at less than 140' and be done as a no-decompression dive. Carefully watching your dive time is critical, and of course, a safety stop is always in order. The artifacts on the Isle Royale Shipwrecks are seen by hundreds of divers a year and have value where they are to all visitors. Please leave them on the wreck so everyone can enjoy these tidbits of history.