This report concentrates upon the factors governing the design of sea anchors in order that they should fulfil their twin functions of providing stability and of slowing drift rate.

Inflatable liferaft sea anchors have been found to fail or work unsatisfactorily in practice. In some cases failure has been due to insufficiently robust construction to withstand the loads applied during the intermittent loading due to wave action. It is also important that The sea anchor or drogue should provide a drag force appropriate to the liferaft and that its action should be stable. If the drogue should be tumbled by wave action it should be able to recover its original configuration without tangling.

New designs, having considerable advantages over existing designs, are described. These take the form of stoutly constructed cones firmly attached to their warps and with prevention against tangling.