Stability at higher speeds

[dbsea]

I have a 2016 C-30CB. When I stay around 3000-3100 RPM I am generally doing 16-18kn. When properly trimmed (bow waves breaking about at the end of the bow rail), I don't need to make many trim tab adjustments so long as its calm, etc. I find that when I push the boat faster, up to 3200-3300 RPM (20-22kn) if I'm in a rush (yesterday for example, when it was 82 degrees on Lake WA and I'm trying to beat the darkness back to the dock), the boat gets a bit squirly and requires a lot more trim tab adjustment and either steering input or having the heading hold on. Is this common? Is it that by increasing my speed that more of the boat is out of the water and I need to trim down more? Thoughts?

 

[Ralf H]

Hi Dave,

That's essentially correct. However, I can't tell you for sure without running your boat myself. I wouldn't say that the boat gets squirrelly at higher speeds, but I don't know the exact conditions, etc. Go ahead and be a bit more generous with the trim tabs and see if that helps settle the boat down. It definitely should. Let us know.

Cheers,

Ralf

 

[Cutwater28GG]

I’ve found the same on the 28. Anywhere near flat out and it’s a damn handful. Serious risk of it spearing off in a direction based on the last wave that hit the bow from the side.

 

[Cutwater28GG]

What I’ve deduced so far is with so much of the boat out of the water on plane it takes just 1 wave for the bow to catch and really upset the balance of the boat. Which causes a roll and the the boat turns with the direction of the roll.

 

[dbsea]

good to know i'm not the only one! I rarely push the boat hard, so it's mostly a non-issue but want to understand the handling characteristics and ways to manage if I do have to go fast.

 

[Bird Dog]

I also have a 2016 CW 30 CB and have had trim tab / stability issues. I purchased my boat a year ago and when taking it from Everett to Anacortes first noticed the helm pulling hard to starboard, or more correctly, requiring correction. The conditions were windless, rainy and calm and I had read on this forum that these boats "tended to do that". I soon learned that it's a trim tab issue. After a lot of hours and different settings I have come to realize that the tabs are one of the most important items as far as steering is concerned, as well as fore and aft trim. On my boat it's a finesse thing, but I'm able to trim it to my liking if I play with it.

Like you, I don't run my boat hard but my tabs are now being retrofitted at NHD in Anacortes. My problem has been the slow reaction time of the tabs and not having an indicator or gauge to know where the tabs are at any given time. The original Bennetts are analog rocker switch driven with no indicator gauge. I'm upgrading to the new digital version with a brain and a position indicator gauge, plus other helpful features. I'm looking forward to the results.

I hope to sea trial the new tabs mid-November when I'm back out to Anacortes.

 

[dbsea]

I also have a 2016 CW 30 CB and have had trim tab / stability issues. I purchased my boat a year ago and when taking it from Everett to Anacortes first noticed the helm pulling hard to starboard, or more correctly, requiring correction. The conditions were windless, rainy and calm and I had read on this forum that these boats "tended to do that". I soon learned that it's a trim tab issue. After a lot of hours and different settings I have come to realize that the tabs are one of the most important items as far as steering is concerned, as well as fore and aft trim. On my boat it's a finesse thing, but I'm able to trim it to my liking if I play with it.

Like you, I don't run my boat hard but my tabs are now being retrofitted at NHD in Anacortes. My problem has been the slow reaction time of the tabs and not having an indicator or gauge to know where the tabs are at any given time. The original Bennetts are analog rocker switch driven with no indicator gauge. I'm upgrading to the new digital version with a brain and a position indicator gauge, plus other helpful features. I'm looking forward to the results.

I hope to sea trial the new tabs mid-November when I'm back out to Anacortes.

Thanks for all that insight. Auto trim and digital gauges are on my list too. Maybe this winter…

 

[scross]

Dave,
Just a suggestion on the auto trim. One of the C-28s we looked at last month had the auto trim installed. Installation of the auto trim required a larger hydraulic fluid reservoir. Installation of the entire system ended up costing the owner more than double the cost of the auto trim itself. Also, the larger reservoir impacted the operation of the hydraulic cockpit engine cover’s raising function which made me a bit nervous. Don’t know if these issues were unique to this specific C-28 or not. Just recommend some due diligence if you go this route.

 

[Bird Dog]

I failed to mention that the system I'm upgrading to is made by Bennett; there are no new reservoirs needed, just actuators, the brain and wire runs, and the replacement switch and gauge combo. I looked at most of the other brands and configurations and was initially interested in the Volvo Interceptors, which are great on paper but very expensive to retrofit a C-30. Once I learned that Bennett now makes a more current system it solved my issue. These tabs don't run off of a GPS so there are no automatic adjustments; they are just more accurate and have a faster response. The one nice feature is a HOME button, for lack of a better description, which quickly returns the tabs up to the horizontal position. This is especially helpful if one forgets just before backing down, for example.