Dolphin striker

Martingle and Dolphin striker on tall ship Stad Amsterdam

A Dolphin striker is a small vertical or near vertical spar spanning between the bowsprit and martingale thereby redirecting the direction of the tension in the forward end of the martingale slightly more vertically. This vertical component is necessary to more effectively oppose the forestay's mostly upward tension on the forward end of the bowsprit than would be the case in the absence of the dolphin striker.^[1]

On a catamaran such as the Tornado and the Cobra where the mast is stepped on a beam between the hulls the dolphin striker provides support for the beam in order to support the mast load.^[2]

References

1. ^ "Dictionary of Wisconsin History - Term: dolphin striker (maritime)". Wisconsin Historical Society. http://www.wisconsinhistory.org/dictionary/index.asp?action=view&term_id=10297&term_type_id=3&term_type_text=Things&letter=D. Retrieved 10 January 2010. "A short spar perpendicular the bowsprit, used with martingales for holding down the jib-boom. The position is such that a dolphin leaping at the bow of a vessel could possibly be struck by this spar." 
2. ^ "Rules and Restrictions Imposed on Cobra 5 Metre Catamarans as amended to January 1996". Australian Cobra Catamaran Association. January 1996. pp. 3. http://www.cobracat.com/cobra_docs/rules_and_restrictions.pdf. Retrieved 10 January 2010.