Fortress Anchors

No Other Anchor Compares to Fortress Anchors, the Best Value in Anchoring Safety and Convenience


Fortress® Anchors are constructed from a high-tensile, corrosion-resistant, aluminum alloy that is precision-machined into interlocking components with no welds that weaken the metal structure. This results in a lighter, easy to handle anchor providing superior holding power.


Since 1986, the much lighter Fortress have consistently out-performed heavier steel anchors in holding power tests conducted around the world. In the US Navy tests, not only did Fortress® Anchors out-perform heavier steel anchors, they were also able to withstand pull loads that averaged over 200x their own weight…and without incurring serious damage, which was noted in the test report summary:

The fact that Fortress® Anchors incurred no significant structural damage at such high holding ratios suggests that the anchors have been extensively engineered from both the hydrodynamic and structural standpoints.

  • The Fortress anchors had far greater holding power than any other anchor tested.

    The United States Navy
  • We tested the lightweight Fortress FX-23, and the results were remarkable!

    - Bateaux
  • The Fortress Anchor outperforms other anchors of comparable size.

    - Cruising World
  • I've used a Fortress as my primary anchor in sand and mud bottoms for more than 20 years. I have found the Fortress to be thoroughly dependable.

    - Elbert S. Maloney, Author "Chapman's Piloting & Seamanship"
  • Fortress makes it practical for boat owners to carry a large storm anchor they might previously had no room for.

    - Motor Boating & Sailing
  • After almost a full year of heavy-duty cruising, there is no way I would revert to the old heavy steel anchors again.

    - Multihulls, 300 Day Cruising Test
  • The Fortress FX-7 wins again on our second test with impressive performance.

    - Nautica (Brazil), tests conducted in '96 & '10
  • The Fortress FX-23 attained far superior holding power than its much heavier opponents.

    - Neptune (France)
  • Be assured that on the combination of anchors and the clay type bottom we tested in the published test, the Fortress anchor performed absolutely best.

    - PAKRYSS (Sweden)
  • The Fortress is the best fluke type anchor we have ever tested.

    - Pontoon & Deck Boat
  • Fortress carries the 'form, not weight' theory to its logical conclusion.

    - Power & Motor Yacht
  • The perfect anchor? We like Fortress!

    - PowerBoat Reports
  • Fortress anchors have at lease twice the holding power of the other types tested.

    - Practical Boat Owner (UK)
  • The Fortress is hard to beat. We continue to be impressed.

    - Practical Sailor
  • A well made aluminum anchor is at least a viable alternative to the various already proven designs in steel...the Fortress anchors tested highest.

    - Sail
  • With its light weight, quick setting and retrieval, enormous holding power at a variety of scopes, and easy stowability, the Fortress ranked high among all the anchors we tested.

    - Sail, Oct. '06
  • The Fortress FX-16's holding power is excellent in all conditions.

    - Trailer Boats
  • Fortress represents the best in anchor technology.

    - Yachting
  • The Fortress set very quickly during our tests. It outperformed all other anchors by a significant margin.

    - Yachting Monthly (UK)
  • The Fortress's ability to dig in instantly and hold was astonishing - especially as it weighs only 22lb, one of the lightest anchors tested.

    - Yachting Monthly (UK), Dec. '06
  • We were astonished by its holding power of more than 3 tonnes, equivalent to the cable load of a 12m (40ft) yacht in a hurricane.

    - Voiles et Voiliers (France), July '09 & Yachting Monthly (UK), Nov '09


Boat Lengthft16'-27'28'-32'33'-38'39'-45'46'-51'52'-58'59'-68'69'-89'90'-150'
Fortress ModelFX-7FX-11FX-16FX-23FX37FX-55FX-85FX-115FX-125
   Weightlb (kg)4 (1.8)7 (3.2)10 (4.5)15 (6.8)21 (9.5)32 (14.4)47 (21.2)60 (27.2)69 (31.1)
   Replaces Steel Anchorslb6-910-1314-1819-2833-5050-6570-9090-100100-170
Working Loadlb7009001,2502,0003,0004,0005,2506,0006,750
32° Hard Sanding Holdinglb2,8003,6005,0008,00012,00016,00021,00024,00027,000
45° Soft Mud Holdinglb8401,0801,5002,4003,6004,8006,3007,2008,100
32° Soft Mud Holdinglb4205407501,2001,8002,4003,1503,6004,050
"A" Shank Lengthin (mm)24" (610)27" (686)31" (787)36" (914)40" (1,016)46" (1,168)51" (1,295)51" (1295)56" (1,422)
"B" Fluke Lengthin (mm)14" (356)16" (406)18" (457)21" (533)24" (610)27" (686)30" (762)33" (838)33" (838)
"C" Stock Lengthin (mm)19" (483)22" (559)25" (635)29" (737)32" (813)37" (940)41" (1,041)45" (1,143)45" (1,143)
Proof Coil Chainin (mm)3/16" (5)1/4" (6)5/16" (8)3/8" (9)3/8" (9)1/2" (13)1/2" (13)1/2" (13)1/2" (13)
Nylon Rope **in (mm)3/8" (9)3/8" (9)1/2" (13)5/8" (16)3/4" (19)7/8" (22)1" (25)1 1/4" (32)1 1/4" (32)
Shackle Sizein (mm)1/4" (6)1/4" (6)5/16" (8)3/8" (10)7/16" (12) 1/2" (12)5/8" (16)5/8" (16)5/8" (16)

NOTE: Hard sand holding power figures above represent loads actually achieved on production Fortress and Guardian anchors under controlled horizontal pull conditions without dragging or resulting in disabling structural deformation.

** Rope recommendations are based on manufacturer’s ratings of 25% of breaking strength. Rope must be in good condition.

For tech questions please email us at and a Fortress Marine Anchors representative will respond in 24-48 hours.