Posted by: rjd9999 on Oct-29-12 6:29 PM (EST)
I'm not a big fan of rudders in the surf. When broached, as someone stated, the rudder may impact your ability to react, but more importantly, I've seen them hit bottom in shallow water. Since the rudder on a broached boat is perpendicular to the wave action, all the force lands on that tiny piece of metal and it isn't designed to withstand lateral forces of that magnitude.
Generally, one of two things happen here - either the rudder digs in the bottom and is damaged/destroyed as the boat attempts to use it as a pivot point, or the rudder remains intact, and the boat pivots around the rudder. Neither is a particularly good result.
Note that when a boat is pushed from behind, the rudder is effectively useless. Rudders help to maintain the tracking of the boat/ship because the rudder is encountering a counter force which it deflects at the rudder angle. It is the water pressure against the side of the rudder which makes it work and there is very little of this pressure when the boat and water are moving in the same direction.
If you live near a shipping lane as I do, you will see that large ships require tugs when traveling with the current because the rudder effectively has no stationary water to push against. Tugs are not used when the ship it fighting the current because the extra force against the rudder actually improves ship handling.
So, when leaving shore, it's fine to deploy the rudder whenever conditions warrant, but when coming in through the surf, it is pretty much useless and may cause a capsize.
Rudders are intended to improve tracking over long distance cruises where myriad forces (wind, current, waves, etc.) may impact the ability of the hull/paddler to continue in a straight line.
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