A drogue is a specialist piece of equipment used to help slow a vessel in big weather where there is a danger of surfing down large waves into the wave ahead. Doing so can result in a broach, pitchpole or flooding, none of which are either fun or advisable!
A drogue should not be confused with a sea anchor. Whilst drogues are used to help control a vessel’s speed when underway, a sea anchor is deployed when a vessel is not underway and when you wish to ‘hunker down’ in really bad weather or when your crew can no longer effectively sail the vessel. As the name suggests, when a sea anchor is deployed, you are not under command. In contrast, when streaming a drone you are still under command and making way.
Sea anchors are usually set from the bow, keeping the bow into the direction of the waves. Drogues, on the other hand, are set from the stern so as to slow your progress. In either case, it’s important that you make sure to practice deploying both in good conditions rather than leave it until bad weather is imminent!
It should not be underestimated how much force will be transmitted from the drogue or sea anchor to the vessel and it’s important that they are properly attached to the correct strong points. It’s also worth considering how you will recover the gear after deployment, especially when in an emergency. For example, when the vessel is being broken up by the sea state or you are being driven towards a lee shore. And make sure not to get the lines and gear around your rudder, keel or propellor during the process!
Many sailors have successfully streamed warps or lines off the stern in an effort to slow their vessel in big weather. In extreme situations, when you have lost steering and you cannot use your emergency tiller effectively, streaming lines or deploying a drone can be a useful solution in the right conditions.
In such cases, it’s important to make sure you are able to recover these lines (usually by having them on winches). This has the added benefit of being able to ‘trim’ the length of your lines so as to regulate boat speed in varying weather conditions. In the worst case scenario, have a sharp knife at hand!