I have seen some commanders with after market trim tabs installed. Doesn't the design of the Commander hull enable it to get itself up on a plane pretty fast with the BB Fords and Chevys? Given that I going back in with the Crusader 454's, I wonder if I would need trim tabs. Most of our cruising will be here on the Chesapeake Bay. The Bay is famous for it chop. What's the scoop on trim tabs?
Jerry
Jerry I have them on my 35 and so does Tim Toth he taught me a long time ago how to set the tabs and it makes a huge difference in cruising speed and fuel consumption to trim the boat out right. I know Paul doesn't use his or has them in a fixed position but I wonder how much fuel economy or better speed he could gain if he did use the tabs. I have my motors mounted so far forward in my boat you would think there is no need for any tabs but there is. Tim has the 427's in a 35 Commander and he uses his tabs and his configuration shouldn't be that much different than yours. Another friend has a 41 and he uses his also again a big difference in cruise speed. I adjut mine everytime the boat goes out and retract them when coming in to dock. I really don't know of any boat that doesn't have trim tabs anymore. I personally would opt for the tabs if nothing else they aren't that expensive and the fuel savings could make a huge difference. A set of Boat Levelor Tabs 18 x 9 would only set you back about 350 with shipping that includes everything you need. You may even find them cheaper elsewhere but you can check them out here I have purchased from this company before and have had no problems with them.
Have you ever seen a 38 cruising at any attitude other than just about flat? The 38 hull rides basically flat right out of the box, at least on a 38 it does. If you use trim tabs to force the nose downa and MAKE a boat run flat, you are creating friction and drag pressure at the tab, and forcing the hull into an increased wetted area.
Trim tabs may have a place on an aft heavy boat that just wants to run with the bow pointed into the air, but a 38 Express doesn't have this problem, in my experience. As a result, my tabs are set flush with the bottom of the hull in a fixed position. If the boat is heavily loaded with a lot of people on that aft deck, then yes, I may actually be able to use tabs, but don't Does that make me a bad person? I hope not! Ha!
Some Commanders had integrated tabs like this one, belonging to Bob Baillod
This photo is showing a spare prop, by the way.
Here's my 1966, and I do believe this is a factory installed trim tab situation, because I have seen dead on identical installations on other boats. Note the small cast in wedges too. No wonder she rides flat.
OK guys those of you that have 38's do you use your tabs if you have them? I would really like to hear from some of you as to wether or not you use the tabs or like Paul you say you dont need them. I kno win every picture I have seen of Paul's boat yes it is riding flat but he also makes the comment that he as them set flush with the hull so to me he is using tabs just without any down angle on them. I know mine in the uppermost position are not flush with the hull so is the fact that he has them set flush making a difference or not?
Here is a shot of mine in this picture they are positioned way down close to fully extended I would think but not sure. Oh and by the way that picture is from the brokers website before I bought the boat it looks much better now than it did then.
When I pilot, I use trim to take some of the pressure off the control stick and make the plane easier to fly. I give up some efficiency to achieve this. And a variety of reasons (variables) means that I use a variety of settings from flight to flight and sometime within a flight. Maybe there is more to this discussion than the hull shape of our favorite boat. Paul is a River Runner. I don't know where Mark hails out of, but I bet Mark runs into some wave or tide effects that Paul doesn't. The over all, long term measured data average distance between waves on the Cheasepeak is 25 feet. Waves on the bay are a function of current, tide and wind and bottom. It seems that a function of these variables could call for the trim tabs to be positioned differently trip to trip or day to day, but that the boat could certainly get along without the tabs just fine, but not as efficiently. Each time a Commander goes out, its hull is constrained by different weight placements,i.e. number of passengers, where they are placed, gear weight and placement on board, fuel and water weights on board. You get the picture.
Now, given that Paul is a purist dear to our hearts, I would ask: if you were able to hold all variables constant except for going down current vs. going up current on a river, would trim tabs make one of the directions more efficient or equal to the other? Now, if it was just you and your lovely wife headed down river at an RPM of X vs. 15 guests from the local weight watchers club sitting on the after deck chairs and you were headed up the same place in the river that you came down with Janet earlier at the same RPM of X, would trim tabs make one or the other more efficient or at least equal to the other?
I think there is more to trim tab function than just helping the hull get on plane fast, but my original question still remains unanswered. Do the tabs make that much difference on the hull performance to justify their costs? Or something like that? Rob, you cruise the bay. What's your experience?
Jerry
Jerry
Jerry I am out Sandusky OH on Lake Erie where the avg distance between waves is measured in seconds not feet so yes trim tabs are set different each time depending on water/wave conditions I have seen wave actions at 6 to 8 foot at 5 seconds apart which is some really nasty stuff. Coming back from Algonac last year Tim and I were running at some seriously reduced speeds while our friend in the 41 blew past us and left us in the dirt so to speak he put it up to cruising rpm and left it there for the entire trip. Tim and I were down to 13 to 15 mph and I was using no tabs in the following seas better yet we has seaweed on the cabin top when we got back to port. So it does depend on load, water conditions, and all the rest where they get set.
I have had Changing Channels for 9 years. Not one time have I felt that I would get a better ride if I had trim tabs. I like Mark boat on Lake Erie so I have seen just about every kind of wave there is. I also was on that trip from Algonac (AKA the trip from hell)Due to the waves of course. I don't think there is a boat made that would have had a good ride tabs or not!! My boat has the planning wedges faired into the bottom. They seem to to a great job of getting the boat at a proper running attitude.I asked Tim how much gas he burns from Sandusky to Algonac and he figured about 66 gallons per motor. Changing Channels burnt 67 gallons per motor with out trim tabs. I am also running 427's.
Matt O'Donnell
Note: The previous owner removed the tabs before I purchased the boat.
Matt, you have the same cast-in wedges I do on my '66
March 20 2008, 4:27 PM
I think CC resorted to external trim tabs like your boat had, after using the integrated tabs for a while. Your installation looks dead on like mine on FXA-38-3004-R.
Okay, where to start? First variable for my situation that is different than most 38's is that mine is powered 265hp/SBC's. I do feel she lacks some tork but, top speed is respectable. Somewhere in the low 20's (knots) depending on conditions. For maximum speed I have to put the tabs all the way up. If I introduce any tab the bow starts to plow and the speed drops.
Due to the amount of boat traffic between Marblehead Penninsula, Kellys Island, Catawba Island and South Bass Island, we have choppy conditions almost every weekend. We refer to it as the Devils Triangle. It looks like something out of the movie "The Boatniks". This 27' Commander was bobbing around fishing on a very calm day.
My guests can enjoy a quieter and less bumpy ride if I dip the bow in just a bit while running at cocktail hour speed (that is just off plane or less) . Not efficient but, less beer on the deck. The TEAK deck
I agree with Mark about the heavy sea conditions, NO TABS! especially in following sea. It may be a lack of power or less weight in the stern (without the big blocks) that makes my boat generally feel a little bow heavy. Once in a while I will get in a deep trough and the bow or keel digs in and wants to have a mind of its own. It takes a huge amount of steering input to correct, and this is with the tabs all up.
My boat does have the molded in wedges similar to Paul's but, not exactlly the same. My bottom line on trim tabs is this; If mine went out I would set flush and leave 'em. Even with the SBC's, I don't need them to get up on plan
the wedges in the photo look exactly like the ones on my 1966 and they were most likely a factory checklist option for people who wanted the equipment, based upon how they planned to use the boat. My installation looks "very stock" on the inside too, very manufacturer-like install from the transom to the helm control station.
Somehow I think the integrated cast-in trim tabs were a bit of a problem for Chris Craft. Of all the hulls I've seen, I don't see to many of them. If you're loading your boat with lots of guests, maybe using it for fishing, whatever, if you have the tabs you would probably find they could be used to advantage under some conditions, but as noted, neither Matt or I have found any need for them......mine have been set flat with the bottom of the hull for the last 10+ years and I never thought it was worth the time to even check the fuse. To me, they're useless, because my 38 rides as flat.
I'll bet a box of doughnuts that CC discovered it was a LOT easier to make that hull without the cast in tabs, and a whole lot easier to have people check the box and pay extra for the external installation (on the 38 Express). Now the question remains, what is the chronological timing of the integrated tab during the 38 Commander model run?
On my way to look at a 1965 F-150, do I need it, heck no but it has a big block Ford momo and would make a cool tow vehicle for the skiff.
Jerry
I have never owned a boat (except 13' outboard) with out tabs. I always use them. On my 25 Chris (Catalina 9'6" beam) on the bay they were great. I would adjust the tabs if someone would shift sides or move fwd/aft. On the 31 there is not much changing when one person switches sides of fwd/aft, but 2-3 makes a difference. But when necessary I do adjust them. I also tend to run bow down, as I believe the bow is designed to cut the water and if it is coming out you are tending to pushing more water, however this may contradict what Paul said about less wetted area and less friction. Also if I run my engines up to 2700 RPM with no tab and start adding (lowering tab, bow down) I gain 200 to 300 RPMs. So I am decresing load on the engines but creating more friction, but not pushing water from mid hull.
I also like being able to vary attack angle during rough/changing sea states.
My father had a 27' Owens with a 327 Chev. first year with boat, no trim tabs, did a trip from Delware River above Phila to Chesapeake City in C&D Canal, ran out of gas entering Engineers cove 49+ gallons. Next Year installed Trim Tabs, same trip 35 gallons.
I have always had Bennett Trim Tabs. I like the installation and never had a problem. I was on a boat with Boat Levelors, twin engine flybridge wood with many people, running at high speed and control solenoid stuck for one tab, boat took hard nose dive to one side, took a little for Capt to figure what was happening, wasn't pretty. I also don't like the exposed hose on the boat levelor tabs.
I agree with all Lee had to say. I wouldn't own a boat without them. My boats always had them when I bought them. I talked 2nd PO of my Commander to put them on her before I ever thought I would by her. He got a deal on Bennetts, I think their 18"X9", I think they're a little small but they do work, so it may be just a visual thing, and my 25 Chris had bigger tabs 24"x9".
Rob
My 31 has the molded wedges and also has tabs (wrong size 36 x 12) I have a set of 36 x 9's that I took off a boat we scrapped and those are the correct size. These are what I'm going to use.
Ok Ok I give it seems the 38 is a much different beast than the 35 and we dont have the molded in wedges or whatever it is you guys got. So we need tabs and I guess so does the 41. Like Chris said Lake Erie is a different monster and it gets ugly faster then anything else in the world so they say, too shallow and stretches for a long ways right along a weather front etweeen Detroit and Cleveland if you dont believe that just watch the weather channel. It seems strange to me with my motors so far towads the front that I use as much tab as I do but Tim uses his so... who knows oh well Alan Jackson is on MTVHD so im going back for another beer and more good music.
I put my foot in my mouth too soon it seems. Lee sent me an email that has a lot of good info in it and I am copying part of it below.
Jerry:
Personally, I have found that if and when I use tabs, it is only for leveling the load side to side. ( Thus one of the trade names "is" Boat Leveler corp"
Your scenario about using them to offset loads unequally on board is correct. Tabs being used to "set a boat's bow down" will as you say alter it's over bottom efficiency. However, in certain times on the bay, the chop and sloppiness and "confused" seas, will be much easier to handle with a little "bow Down" and into the waves.
Personally Yes, I feel they are well worth the money spent, as long as you know why you want them. And I think you have done the homework.
One other note. Not sure which commander you have, but some of the the 38's had "wedges" under each side of the transom that were glassed in, ( Mine has these) Should you leave these in there, the tabs will basically become useless, as while on plane the tabs won't hit water, I don't believe. My 27 didn't have these, so it wasn't an issue. I'm going to copy this to Dick Morland, as he can give you some more specifics concerning tab usage etc.
regards,
Lee
This is Jerry again. Like Chris, I think I will get an ale and think about it some more!
Jerry
First of all I realize that you want to minimize tab use in a following sea- BUT
I think you just hit on the the best reason to use tabs - that being side to side leveling. Last year at the end of the season, I was heading to the storage facility and, not having the luxury of of waiting for nice weather, had to deal with a somewhat impressive following sea partially from the port side. The boat was getting a little testy from time to time when conditions came together and raised the water level on the port side causing the boat to slew to that direction. I found that putting the port side tab down a little (just a little) and correcting to starboard with the rudders improved the situation somewhat and gave the preloaded rudders a quicker response. Only got about 15 minutes of running in with this setup but I'll probably have a chance to refine the technique a little this year. Just my .02
Eric
With due respect to your source, I don't beleive that 38 has ever been in the water under his ownership. When it comes to the 38 there's simply no substitute for actually running a 20,000 pound hull with a 13' beam on the water. Conversely, I would be reluctant to comment on the viability of tabs on a 27, because I've never run one.
Matt and I have a collective 21 seasons of running a 38 on a plane, and we share the same opinion of the tabs.
The comment about the tabs being out of the water caught my eye. During my twelve year period of burning gas in a 38 I've seen my trim tabs "in the water" to the same degree as the bottom of the hull.
For me on the flat water of the Cumberland, I never had the need for tabs and that's why mine were set flat and left alone. Matt does his boating on Lake Erie, doesn't appear to have the need, but that doesn't mean they would not help level the boat if you wanted to, or help lean into the wind on a crosswind approach, help in a following sea, etc., if you elected to install them. Personally, if you don't have them now (on your 38), I'd save my money.
I don't have as much time burning fuel in a 38 as some of you guys do, but I do have tabs, and they are the same kind of outboard tab (with hull wedge) as some of the pictures. I also stayed in a Holiday Inn Express, and that means I have an opinion (too)! I'm running the same kind of water Paul is here on the Tennessee River, and although my tabs work, I never use them. I had the shop fix mine when we purchased the boat. We played around with them but never really had any occasion to set them anywhere except flat. On the river water running, they're about as ussless as a..............well, you get the idea. (North Alabama bucholic saying avoided due to better judgement).
Having said that, those tabs are always in the water when the boat is moving at any speed. I think the boating community looked at tabs as a marine device people should have, and instead of CC telling people they probably didn't really need them on a 38, they were probably happy to sell them. I can see some uses for them, but honestly, we haven't had enough of a load on our 38 to really change the running angle that much to mess with the controls. When we're loaded, it is generally for a slow cocktail cruise. Some of you guys up on Lake Erie doing the long range cruises, undoubtedly know what tab setting gets you the best fuel milage. Here on the river, we get great milage running downstream, by the way, and poor milage running against the current. Tabs don't help much in these waters.
On some of the smaller boats I can see where they would be a big help. On the larger boats I don't think tabs do anything but cause turbulence, since there probably isn't enough lifting being done on that small footprint to really change the running angle of a big boat. JMHO
Very interesting thread, guys. My comments are for the 38' hull (only).
I think we've hit on an interesting fact that trim tabs are less and less useful as the length of the hull increases. I don't think we'll see too many tabs on a 45' TF, for instance, because the tabs really don't have enough moment resistance to affect the attitude of something that big. I think the 38 is on the cusp, or beyond the cusp of where tabs are of any meaningful value, due to the unique combination of the LOA v beam dimensions, center of gravity, lifting strakes, semi deep V hull combo, etc. Therefore, "tabs" are not a universally necessary device on "all" hulls. I think the points are well made, that the smaller boats can benefit greatly, and the larger the hull the less value these things are..
I have tabs on our 38, and like some of the others who have posted, have seen little need for them due to the way the 38 rides fairly flat. The nose is really never pointed to the sky like some of the boats I have owned in the past. If people want these for their boat I'm sure they will provide some degree of trim adjustability, and always provide the option, but I am doubtful if they'll ever pay for themselves on a 38' hull.
There is always a compromise between "wallow" and "plow" on a hull. Too much lard on the aft deck, or too much center of gravity aft due to engine placement in the hull, can create a wallow at various speeds, and tabs can help put the nose down in this situation, probably creating a fuel consumption efficiency too. The 38 is probably as close to a mid aft inboard location as any cruiser afloat, extremely well balanced boat. Using tabs to lower the nose can create a plow condition, pushing more water from the nose and creating drag at the tabs too.
The 38 is a well balanced work of art. Width to length ratio has a lot to do with the ride. The longer the ratio, the less need for the tabs. Tabs may help tune the ride, but we rarely, if ever, use ours because there seems to be little reason to do so.
Rather than drill holes below the waterline to install trim tabs on a 38 and spend hard earned cash, I would suggest to people like Jerry who are restoring a hull for action, to put the boat in the water and give it a try. Later if you have the liquidity and want to drill holes, you can do so next time the boat is on the hard.
The points you made about length, width and center of gravity make me appreciate the design and ride of a 38 even more. Never even thought of tabs on mine, it runs as flat as an inboard runabout.
Does that make me a bad person? I hope not! Ha! 
