Re: Fin shapes


r0w3r wrote:
> Looking at different boat types (singles in particular), there seems to
> be a huge range of design for the humble fin and I was wondering why
> there are so many types and what the pros and cons of each type are.
>
> Also, does a deeper fin provide more stability or just more drag
> without the improved stability?
>
> What's the most efficient shape of fin and if there is one preferred
> shape for this, why is it not fitted across all boats?

Skegs for 1x's vary because many factors affect the size and shape of
skeg a designer chooses:

- tracking - I don't know of any 1x's designed specifically for turning
(I wish someone did, I prefer head and stake races!), the primary aim
is straight line performance, and the designer's concept of how
important tracking is versus drag will influence the choice of skeg
- stability - a less stable hull may require a skeg with a greater
stabilizing effect on lateral roll, again depending on the designer's
expectation of the users' skill levels
- the hull's intrinsic tracking ability - a hull with a deeper bow
(Filippi, Hudson, Empacher) may naturally track straighter than one
with more rocker (van Dusen, Resolute) and hence a smaller skeg may
suffice; on the other hand, reducing skeg size on a hull with more
rocker may yield greater improvement in manuverability than it would
with a deeper hull (I've reduced the skeg size on my Empacher by >50%
but my teammate can still turn his Resolute far faster, especially with
his smallest skeg installed)
- skeg location - further aft => straighter tracking, other things
being equal
- cross-sectional shape (foil vs plate) and overall skeg shape (deep
and short vs. shallower and longer)

The situation for 8's is probably somewhat different.

.

Relevant Pages

  • Re: Is there an optimum fin shape?
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    (rec.sport.rowing)
  • Re: Skeg Placement
    ... In the states we call it a skeg, with the possible exception of novice women. ... I was actually wondering what factors the expert boat builder ... the need for the boat to hold a set course in a cross-wind without undue crew input ... It's a messy set of compromises to make, & what works with one hull design may be quite inadequate on another, so it really is not possible to give rules. ...
    (rec.sport.rowing)
  • Re: Vespolis Video on hull design
    ... think we were talking about sacrificing some of the hull stability for ... Good fin skeg can with really minimum increase of surface and drag be ... I'm pretty sure that many crew that had just few months to get ready ... They'd get that extra stability from a better fin system. ...
    (rec.sport.rowing)
  • Re: dragged the outdrive and
    ... I/O with fin below prop ... mercruiser alpha one fuel injected 6 cyl ... Chip or bend or break the skeg. ...
    (rec.boats)
  • Re: dragged the outdrive and
    ... I/O with fin below prop ... mercruiser alpha one fuel injected 6 cyl ... Chip or bend or break the skeg. ...
    (rec.boats)