My hunter 33 (1977) sails wonderfully under most conditions, but i experience a sudden loss of rudder control at high wind velocity and large heel angles. In particular, at larger heel angles, it rounds up uncontrollably, even with maximum trimming to move CE forward. I've been told that this was because these boats were built with an undersized rudder, and hadn't questioned that explanation until late this season, when i noted that every time a the boat hit the point where rudder control was lost, a heavy trail of bubbles could be seem in the wake in line with the rudder. So i'm now fairly convinced that rudder ventilation is the culprit(not an undersized rudder or stalling of the rudder) . I'm also thinking that i'd enjoy my heavy weather sailing better if i managed to fix this. (There is a little bit about the ventilation issue in "Yacht Design Explained: ...", by Steve Killing, Douglas Hunter, pg 117)
So i'm thinking of doing some rudder mods as a winter project, in particular adding one or more anti-ventilation plate(s).
But now that the boat is out of the water for the season, i'm regretting that i never managed to actually watch the root of the rudder under round-up conditions. So i'm left wondering how far down the rudder the plate should be installed. (yeah, that means that i'm missing direct observation of the ventilation effect, so i'm left to infer it from the 100% correlation with round up and bubble trails)
I'd appreciate any comments on the subject, or answers to these questions:
Has anyone else experienced excessive loss of rudder control and round up on these boats? Anyone observed the bubble trails i'm seeing? Anyone have a sense of how much the top of the rudder comes out of the water at larger heel angles on an h33 1977?
So i'm thinking of doing some rudder mods as a winter project, in particular adding one or more anti-ventilation plate(s).
But now that the boat is out of the water for the season, i'm regretting that i never managed to actually watch the root of the rudder under round-up conditions. So i'm left wondering how far down the rudder the plate should be installed. (yeah, that means that i'm missing direct observation of the ventilation effect, so i'm left to infer it from the 100% correlation with round up and bubble trails)
I'd appreciate any comments on the subject, or answers to these questions:
Has anyone else experienced excessive loss of rudder control and round up on these boats? Anyone observed the bubble trails i'm seeing? Anyone have a sense of how much the top of the rudder comes out of the water at larger heel angles on an h33 1977?