Comparison · Posted by the MoorSafe team · · 4 min read
Mushroom anchor vs MoorSafe: what's different, and what isn't
MoorSafe is a mushroom anchor with one change. The change is on top, and everything underneath is familiar. If you set or maintain moorings, most of this will already feel known.
What stays the same
- The bowl. The same concave mushroom bowl. It sinks into mud and gains suction over weeks, so holding power isn't compromised.
- The base. A cast-iron base, like the anchors you already set.
- The gear. The same chain, shackles, swivel and pennant. Attach at the top eye.
- The setting. Lowered with a mooring barge or service boat, at the same scope and with the same practice as a mushroom.
- Who can install it. Any mooring service provider will be familiar with the process.
What's different
- Three bars that form a cone. Three symmetrical bars rise from the bowl to a single point above the stem. The stem is no longer a bare vertical post.
- Welded steel bars, finished in high-visibility safety orange.
- Designed and built in Maine, and patent pending (U.S.).
Why the cone matters
On a traditional mushroom anchor, the stem is a vertical post. As tides, currents and wind swing the boat, the chain rotates around it, and once it catches, every cycle pulls it tighter. That's chain wrap, and it can shorten your scope, raise peak loads, pull mooring balls under at high tide, and lead to chain or shackle failure or a boat breaking free. (The full explanation is here.)
With a cone above the stem, the chain has nothing to catch on. That significantly reduces the risk of chain wrap.
What testing showed
A traditional mushroom anchor and a MoorSafe prototype were tested side by side, both at 300 lb.
| Test | Traditional mushroom | MoorSafe |
|---|---|---|
| Tensile strength to failure Yale Cordage, Saco, on a 100-ft bed rated to 1.3 million lb | 38,560 lb, stem fracture | 40,657 lb, joint dislocation. About 5% higher. |
| Breakout after 28 days on the seabed Casco Bay, same muddy bottom, pulled by a lobster boat on a 75-ft chain at 3:1 scope, read on a 4,000 lb digital indicator | 1,575 lb, partially buried | 1,295 lb, fully buried |
The tensile result shows that adding the bars did not weaken the anchor, and that the failure moved away from the single stem. The field test showed comparable breakout, with MoorSafe fully buried, and holding keeps improving as sediment consolidates.
These tests used 300 lb prototypes. The MoorSafe offered today is the 400 lb, and results in other conditions may differ. Full details are on the test results page.
Side by side
| Traditional mushroom | MoorSafe | |
|---|---|---|
| Bowl | Concave mushroom bowl | Same concave mushroom bowl |
| Above the stem | Bare vertical stem | Three-bar cone |
| Chain, shackles, swivel, pennant | Yours | The same ones |
| Installation | Mooring barge or service boat | The same |
| Tensile test (300 lb prototypes) | 38,560 lb | 40,657 lb |
Which size?
MoorSafe comes in one size today, the 400 lb. It's recommended for boats of about 30 to 40 ft, or for heavier displacement and moderate exposure. Sizing depends on displacement, scope and exposure, so we confirm it with you before an order. Looking for a larger size? Send us a request.
Ready to compare for your mooring?
Tell us your boat length and your harbor, and we'll help you decide. Pricing is by quote and excludes chain, hardware and installation. Shipping is quoted by destination.