C21

[vincentc21]

Hi,

I haven't posted since November 2009 when I started my C21. I finished my boat about a year ago and probably would have finished earlier if I could have maintained my confidence throughout the project. Unfortunately many unknowning-know-it-alls have a tendancy of scraping away the niaeve convidence sometimes required to complete a project of this magnitude. It is unfortunate that human nature puts emphasis on negitivity and not those positive reaffirming comments from the people who have built things with their own hands and understand that someone somewhere has to build the things we all live, work and play in.

It is amazing how building a boat reveals to you how many people have also built a boat at some stage in their lives.
A word of caution however, be prepared, it is a mission and one not for those without grit and determination. Having said that I am seriously considering doing it again at some stage in my life. I have made a promise to my son that when he gets older I will help him build his own boat, an experience I hope gives him the statisfaction and convidence it has given me, misus the mistakes.

Now that I have tested my boat in many different conditions, I would say to anyone who is doubting the, strength, handling, seaworthiness, and style of a boat like this, take some solace in my affirmation that I now have 100% confidence in my boat. I have a few things that need finishing, but since fishing now once again fills my spare time I am not to concerned about the few unfinished items requireing my attention.

I have a few questions for the designer;

1 Can I remove the two boxes/seats attached to the motorwell, bulkhead G if I remember correctly? I would like to make more room to walk around, especially if I turn it into a cabin boat and remove the centerconsole.

2 I think the boat is a little to light and in slightly rough weather it really takes a pounding. Swell is fine, but chop is horrible, i really have to slow down to a crawl (<10km/hr heading into 15kn winds, when 50km offshore this is very annoying). I cant trim the motor in any further, and I dont beleive this would help anyway. It seems that the nose just doesnt have enough wieght in it to push through any chop and it just seems to slap very very hard. I left the bung out the other day and the hull got a significant amount of water in it. When I ran like this through the water the additional weight improved the ride considerably. Can I ride like this in rough weather?
I am thinking of turning it into a cabin boat to put more weight up front. Can this be done and do you beleive it would improve the ride at all? Or is it purely a factor resulting from the compromise of ride and stability of the shallow V (12 degrees)?

[jacquesmm]

1. Yes, you can remove those boxes.

2. The C21 (and C19) don't have much deadrise. This is an advantage when it comes to fuel consumption, HP required to plane and economy in general but the price to pay is a rougher ride in a choppy sea.
The bow buoyancy "problem" is not a matter of hull shape but of weight distribution. I don't know how your boat is loaded but as you discovered, it is probably trimmed down by the stern and the consequence is that the hull presents a flat to the waves. This will happen at sub planing speeds: the boat is trimmed bow up and slams.
If you slow down, the trim changes and she runs smoother but if you want to keep going at those speeds (let's say 10 to 14 mph) in a chop, you must change the trim.
That can be done, to a point, with weight distribution or with trim tabs.
First, I would see if I can move some weights forward. In those boats, I count on at least 50 lbs of ground tackle in the fore peak.
If that is not enough, I would consider trim tabs.
Even with trim tabs and weights, there will always be a speed at which the trim is bad. The hull try to "climb" over it's bow wave but doesn't have the power to do it . . .

Move weights, then try trim tabs.
To let the anchor well fill with water is not structurally bad but I prefer the other solutions.

[fastlane]

Vincent,

Nice post. I know i can at least really relate to what you have said.

As for the trim. On my P21 it is amazing how well trim tabs work. I cant imagine running without them here. I have a set of bennet 12x9. On the jersey coast it is pretty much always a sloppy mess and they really make a world of difference.

[Matt Gent]

C21 pictures, please...show off your hard work!

[vincentc21]

Thanks for the replies.

I will look into trim tabs first, because the last thing I really want to do is modify the boat by building a cabin for the primary purpose of adding weight.

I have put some photos here,

http://gallery.bateau2.com/displayimage.php?pid=44406

I'm looking forward to this afternoon. I'm taking an early mark from work and going out of north Stradbroke Island to the night fishing for Cobia and Snapper with my son. Best time of year for fishing, bar the cold.

[Doc_Dyer]

[AMC]

Unfortunately many unknowning-know-it-alls have a tendancy of scraping away the niaeve convidence sometimes required to complete a project of this magnitude.

Just so you know,I plan on stealing that.