I have posted several times in the past about my steering problems and there was a post about a year ago where others indicated that they had similar type issues. There was discussion in that thread about rudder stall or cavitation as a possible cause. I did some internet research and found that the problem occurs when the rudder extends past the transom as is the case with my boat. The rudder stall certainly resonated with my problems. Also, I believe JP had a post where someone addressed the problem, albeit on a smaller Bertram, by adding some fixed tabs (inexpensive way to extend transom).
I figured what the heck it is fairly cheap to build some tabs, so that is what I did. A 12” x 12” sheet of 3/8 fiberglass, 4”x4” aluminum angle and some epoxy and the job was done. The plane of the fiberglass tab follows that of the bottom of the boat. Much easier than relocating the rudder posts! (Huge understatement).
Anyway, I dropped the boat in over the weekend and I am elated to report that the tabs work like a charm! NO MORE STEERING ISSUES. Many thanks to those that shared in the discussions in the past threads. Some pics follow:
I have been off the grid for a while , to much to do at the yard , you could also went for cap's bigger rudders , the ones i see on yours don't have enough depth.
the thing i worry about the most is that after 40 years , you have to come up with the sollution :)
Good Job !!
Gert
Women are like boats ,the older they get , the more money and professional help they need to look beautiful.
Capt Pat's Rudders are on the "list". However, my problem has never been the low speed handling. It has always been the turning at planning speeds. I am sure Capt Pat's rudders are only going to make things better. I can see how deeper rudder blades are certainly going to make a difference.
Now that you mention it, in a round about way, Russ Pagel's "Barbara Jean", now your "Island Girl" was the very first B31 to be fitted with my rudders. You have copy #1. To date, over 400 pairs of those rudders have been sold and installed. Jimmy Gatto is getting a set for his B31 next week...
I remember my machinist saying at the time that he was making them, "You know there's not going to be much of a market for these..." In the first year we produced almost 100 pairs.
That rudder style was OEM from Bertram for a few boats. I refer to them as inverted shark fins... They actually have as much blade surface as do mine, but the difference is in the swept back design. It misses a large vital part of the blade that should be interacting with the prop wash and far too much trailing edge which drags and contributes to the rudder stalling...
But the reason for developing my design was primarily for those ocassions that either you lose an engine or want to slow troll on a single engine, and still want to steer a straight line or even turn against the live engine.
Is it just me or do those rudders look to be set too far back?!... And, no, I'm not saying that because the rudder extends beyond the transom but rather because as I see it, there's a lot of free space between the prop and the rudder...
Possibly a PO moved the rudders back?!... Trying to fix what Pat's rudders fixed?!...
I remember our friends 68 having those rudders but I don't remember them sticking out like that. Fished on his boat many a time and it never had a problem, and no tabs.
I will say, put yours rudders on and she becomes a sports car as far as handling.
No, it's not just you... Here's a comparrison between Jim Bailey's and Vince's. Vince's rudder ports seem to be about 2" - 3" further aft. Maybe more, it's hard to gage exact measurement from an image that not in absolute scale.
I agree with all the observations regarding the rudders not being deep enough and looking awfully close to the transom. It appears to me that is how the boat was originally set up. I do not see any repairs in the hull that would suggest that they were moved. Also, the tabs did not do anything to the performance of the boat when she is up on a plane.
I too have those rudders o my '66, but I don't remember them being set that far back. I think they are closer to the props as I haven't had any problems with them.
Every one of our boats are different. While doing exhaustive work on my exhausts (I couldn't resist!) this winter, Skip and the crew at Brewer Street boatworks discovered that my outlets are a solid 6" lower than his. They are in a COMPLETELY different spot. His are above the waterline partially, and mine are way below.
Both are factory installs. Seems to be the locations of some things were influenced by how big the lunch sandwich was, how much cuban pork was in it or how much cuban coffee they guy drilling the hole had that day. ;) They are one off production boats. Part of the art of the B31.
Capt Pats rudders worked just fine on Resolute, no slip at high speed turns at all, Vince's rudders lose bite by hanging behind transom, Jp nailed it with fixed tabs..easier than moving rudders forward 5" ouch..BH
1966 31 Bahia Mar #316-512....8 years later..Resolute is now a reality..Builder to Boater..285 hours on the clocks..enjoying every minute..how many days till spring?
After reading all of this about rudders and everything else about rudders on other brands of boats for the past 3 years it's plain o me that yur rudders for some reason are way too far aft . My rudders are prob within 6 to 8 inches of prop but I have Bennett tabs probably 9 x 18 that are disconnected and work perfectly to keep wash water down at any speed Think about it they are spring loaded so they stay in the neutral position at all times never have I had any blow outs in any type of sea up to 4 to 6 ft .Your tabs will work but in my humble opin they could be a little larger in both length and width
