We fashioned one out of teak, attached to the pulpit with u-clamps screwed into the underside.
Actually, it wasn't meant as a seat, but rather to serve as a step, because we have to board over the bow at our regular slip (and also to protect the bow light, which on our MkI was factory mounted in a position where it got smashed on a regular basis). But its turned out to be a nice place to park oneself while ambling slowly about protected harbors (see photos). We also added a small teak step to the lower rail of the pulpit; grooves were routed into the top of the seat and filled with black silicone to make it [I]somewhat[/I] no-slip.