230 seamanship secrets
the system. You don’t want weak links anywhere in this area. Anchor rode is made
up of all rope, all chain, or some combination of these two.
Rope. Use all-rope rode only for dinghy anchoring. All-rope rode is
unsuitable for larger vessels because it lacks weight and chafe protection near
the anchor. Th e weight of chain helps maintain the necessary horizontal load
on an anchor.
Chain. Charter companies typically outfit their yachts with all-chain
anchor rodes. Coral and rock seabeds dominate in cruising grounds in the
Caribbean. Large, heavy-displacement yachts over 40 feet long with wide,
buoyant bows make up many of these charter fleets, and these vessels easily
carry 300 to 600 extra pounds of steel chain in their forward anchor lockers.
They are Sherman tanks with Ramada Inn accommodations; it’s a good thing
those steady trade winds dominate in the region!
So what does all this mean for the rest of us? We can learn a few things
about chain from these charter companies. Chain rodes serve as a chafe guard
against bottoms that could easily saw through rope rodes (think coral, sharp
rock outcroppings). Also, the weight of chain helps maintain horizontal loads
on the anchor. Th ese companies realize many of their clients know little about
putting out the proper scope (see “Scope Solutions and Careful Calculations”
later in this chapter). But even on short scope, an all-chain rode usually gives
enough curvature, called catenary, to help keep the anchor set.
Many anchorages in the Caribbean give only partial protection from
the elements. Large ground swells are not uncommon. That makes the yacht
surge up and down, imposing enormous shock loads on its ground tackle.
The sheer weight of chain absorbs a lot of these loads.
Combination rope and chain. A combination rode makes the best sense
for most small craft by providing the best of all worlds: strength, chafe protec-
tion, relatively low weight, excellent shock absorption, and easy stowage.
In a system that combines chain and rope, the anchor rode needs a
bottom-chafing chain length equal to the boat’s waterline length. More is
better, but that’s the minimum for anchoring overnight. For storm anchors,
stow an extra length two to four times as long. Spend the bucks and get
BBB chain. It’s more expensive than proof-coil or high-test chain, but it
has many advantages. The tight link diameter discourages fouling if the
chain piles up on the bottom. It also feeds smoothly in and out of anchor
wells and marries well to windlasses. Cheaper chain breaks without warn-
ing. BBB chain, on the other hand, gives you fair warning of breakage by
first deforming. Replace the chain right away if you notice any elongation
in the links.
The other required elements for a combined anchor rode are detailed
below.