Raising the sails for a leisurely trip across the Gulf of Mexico or an extended trip around the Florida Straits requires more than chartering the best boat, or upgrading to the latest navigation tools. A good trip is dependent upon the proper anchor for your boat. The wrong anchor may not set properly or later drag, risking damage to the boat and injury to everyone on board.
Nautical experts agree that choosing the right anchor doesn’t necessarily mean buying the newest or the most expensive one on the market. Instead, primary factors should factor the size of the boat, selection of anchor rode and storage options. Manufacturers say criteria like the duration of the excursion, the size and windage of the boat, wind conditions and the sea state should also be considered.
Boaters should first identify the bottom conditions for the journey ahead. The type of sea floor — mud, grass, sand, coral or rock — will dictate the best choice of anchors to invest in. Shifting sands and mud will need a stronger hook to anchor the boat steady, while a different hook variety is assured to anchor in the conditions over rocks and coral.
Types of Anchors
No two anchors are the same, requiring different storage and size needs. Various anchors work better in different bottom conditions, so it’s important to select the right one for your specific boat trip.
Plow anchors are the most general purpose anchors on the market and are recommended for sand, thick mud and weedy bottoms. They are fairly large and bulky and usually stowed in a bow roller.
Scoop anchors, similar to the plow anchors, are effective in a variety of sea bottom conditions. Like the sister plow anchors, the scoop anchors are also difficult to store except in a large bow roller.
Claw anchors are popular among mid-sized cruising boating enthusiasts and good for weedy or rocky bottoms. Also, like the plow and scoop varieties, these anchors must also be stowed in a large bow roller.
Danforth-style anchors are a lighter and easier version compared to other bulky anchors. The flat, pivoting fluke is best used in sand or mud, but doesn’t have the capacity to dig into a weedy or rocky bottom. Storage is also easier, either hung from a bow pulpit rail or stored in a flat anchor locker or below deck. Some models may also be dissembled for easier storage, especially in tight ship quarters.
Classic fisherman’s anchor (with its signature tattoo shape that we all know) is the best choice for rocks or coral bottoms. Experts caution choosing a heavier version of the classic fisherman’s anchor to grip the bottom because the flukes are so small.
Mushroom anchors are very light, smaller varieties usually used in inflatable dinghies to avoid carrying a sharp-fluke anchor. The larger mushroom anchors are used for permanent moorings to set into soft mud conditions.
How many anchors should a boat carry?
Serious boaters usually stock three anchors onboard with varying sizes and weights: one main working anchor, one storm anchor (a size or two up from your boat requirement) and one lunch anchor (a light anchor for short trips that is a size or two down). The additional options come in handy to stabilize the boat when encountering changing current conditions or if strong weather drags or pulls a boat in different directions.
Once the anchor type is selected, final consideration must be given to the anchor rode, which is made of chain, cable, rope or a combination of these varieties. The ratio of the length of the rode to the water is known as the anchor scope. A normal scope for a line rode is 7:1, meaning that the rode should be seven times longer than the depth (including the water to deck height). Stormy conditions need a longer scope, usually 10:1 or more. A shorter scope with a 5:1 length is usually sufficient in settled conditions during the day, but experts advise not leaving a shorter scope unattended.