<div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: rgb(255, 255, 255); font-family: Arial; font-size: 12px; ">Bulb shape is at least as vital as everything else under the water.  Various trick shapes have been tried, but the winners all gravitate to an elongated teardrop/torpedo shape.  To maximise the righting moment, the CoG of the weight needs to be as low as possible so some have tried a flat bottomed triangular cross-section, but at the same time drag has to be minimised, so the circular section prevails.  Full size yachts have a crew, who do their level best to ensure that their boat stays as upright as possible, so strangely shaped ballast weights that benefit a boat sitting vertically in the water work for them.  Most model yachts don't, either because of class rules or because the gains are outweighed by the losses,.</div>