Knowing the length of rode deployed is a fundamental and essential part of any anchor system, as it is the sole way of calculating the scope ratio that has been deployed. Typically, rode is divided into segments of a predefined length, e.g. 20 meters, each segment marked and then counted as it is deployed – although electronic solutions integrated with with windlass are becoming more and more popular.
Chain counters are an optional convenience which keep track of how much rode has been deployed (and retrieved), something not easy to measure exactly. The traditional method involves tagging of the rode in a systemized manner, and manual counting (see below). An electronic chain counter however is one more luxury which is intended to permit the entire process of deploying and retrieving anchor to be conducted from the cockpit (or, more frequently, the flybridge of a powerboat).
They typically work by tracking the revolutions made by the gypsy and rope drum of the windlass, these having a fixed circumference. The counter must be calibrated and programmed to suit the particular windlass and rode make-up.
Modern versions available on the market can be interfaced with the control electronics of the windlass, allowing the electronic control of the deployment and retrieval of the anchor and rode from remote.
Manual systems require diligence, standing in the weather watching. Nonetheless, many boaters prefer this to the use of a remote control and electronic monitoring, as this can result in feeling a little out of touch with what is happening in the water. A foot or hand on the chain while the anchor is being set can feel vibrations and movements generated by the anchor which is of great usefulness.
Counting the rode length can be achieved by watching chain tags which need to be installed on the rode beforehand. (Even if an electronic chain counter is in use, it is recommended that the chain is marked at least every 20 meters.) The Rocna designer, Peter Smith, recommends heavy duty reinforced awning fabric in bright colors as ideal for the purposes of tagging (leather was common in the old days). This can be cut into strips about 15mm x 100mm, and attached to the chain link by cutting a slit in one end and threading the tag through itself. They are attached to rope in a similar manner, by feeding through and around one of the strands of 3-strand or 8-braid. Place a tag at most every 20 meters.
These can usually be made out even in the dark, although the use of suitable reflector tape would be even better. These should endure a couple of years or more of use, and they do no damage to the chain or windlass gypsy.
Alternatively, the chain can be marked with paint, but this does not last long as it quickly wears off, and is a pain to both apply and reapply. Rope must still be marked in some other manner.
Chain inserts are also commercially available. These are plastic shapes which snap into the interior of a chain link. These work well but can be difficult to see in the dark. Rope must still be tagged in some other manner.