ESC & ANHINGA stern down trim(was Re: Eeek! Fat chance Tale of a Sailing Canoe)
- Au contraire ;-), the ballast mass is centred where the most bouyancy is, which is abaft midships or actually further aft of that, and if so then it's cantilevering the forward mass of the boat.
Similarly, for the more typical boat with the ordinary rocker that has most of its displacement near or at midships: that is where the ballast mass centres to obtain level trim. If the ESC type carried ballast amidships, ahead of the level trim c o b, - all else being equal - then she will trim down by the bow; and if the ordinarily rockered boat carried her ballast well aft of her cob, or before it, - all else being equal - then she will trim down by either the bow or stern respectively. I'ts a balancing act. If both boats are trimmed level with ballast where it serves best - all else being equal - then that ordinary boat with well designed sections will still trim pretty level fore and aft as she heels. However, the ESC, or any fine pointed stern boat that carries ballast aft of c o b will go down by the stern as she heels.
An upright or slightly heeled ESC type having the major part of her displacement and therefore her bouyancy aft would certainly lift to a following sea ok, but the comparative dynamic situation - accelerating that aft situated ballast mass - may slow the reaction. However, the depth of the bouyant immersed sections adjacent the very stern, the generous freeboard and quite substantial reserve bouyancy aft would I believe see her rise satisfactorily. With increasing degrees of heel under sail that behaviour may change, but, if it were to increase to an "exciting" degree, is it the boat or the seamanship that is lacking? Methinks running off under bare poles would present no particularly unusual performance issue. These small sharpies are for *economically* having the potential of ESCaping seaward to cruise coastwise and not ocean wide in any case - very shoal draft superb gunkholer possessing seagoing capability within reason.
--- In firstname.lastname@example.org, Mark Albanese <marka97203@...> wrote:
> > A boat with lots of buoyancy aft could lift its
> > stern quickly to a following sea,
> The ESC types aren't in this class because the ballast is carried
> so far aft, reducing the relative buoyancy.
> > If the stern has low buoyancy relative to the forward portion of
> > the hull, it can reduce the tendency to broach.
> More common than a pitchpole, yet a twofer.
> No need to get hung up on the ESC's deep stern. It's most probably
> carefully balanced, just right, however experimental. Use it for a
> narrower boat, still with a deep and roomy cockpit, one that'll
> part the following seas and with terrific tracking, if that suits.