DRAGONFLY Trimarans User Forum

Bonsoir
I am the owner of a 25 feet , 20 years old , aluminium trimaran and I wish to buy a second hand DF 800 that I have found around St Malo.
Because of tide levels ( 12 meters maximum in spring tides ), my mooring place is sometimes dry and the boat lying on the sand ( 15 to 20 days in a 5 months summer sailing season , May to September )
My question is :are the crossbeams and swingwings systems strong enough for lying aground and floating twice a day ?
Has anybody this experience ?
Salutations nautiques
J.L Didailler Triagoz 25 "Manx Knight"

Hello Jean Louis,

I live in Jersey and keep my 800 on a floating mooring during the summer in Bel Croute bay and in St Aubins drying harbour over the winter.

I have had no problems at all with the crossbeams and swing wing system. If the boat has dried out on a reasonably level area, there is very little weight or load on the outer hulls; it is easy for one person to rock her from side to side.

The one problem I do have is in St Aubins harbour, which has a very fine, silty bottom. If I don't use her for a couple of weeks, the centre board case can jam up with silt and I have to winch the centre board down.

Hope this helps,

Regards,

Dan
DF800 "Tami Toots"

jean louis wrote:Bonsoir
(snip)
My question is :are the crossbeams and swingwings systems strong enough for lying aground and floating twice a day ?
Has anybody this experience ?
Salutations nautiques
J.L Didailler Triagoz 25 "Manx Knight"

Is the bottom smooth sand or soft mud? The concern would be scratches or deep scrapes on the fiberglass if the bottom were rocky. Also, if the harbor is not sheltered, waves might cause the boat to hit too hard on the bottom. One other thing to consider is excessive wear of the anti-fouling paint.

il y a un triagoz alu a vendre peu cher mais avec un gros travail de de reconditionnement sur un lac a troyes . je me questionne sur l'achat eventuel .que vaut se bateau a votre avis et pourquoi lui preferer un dragonfly ?
merci pour votre aide .laurent

ludion wrote:il y a un triagoz alu a vendre peu cher mais avec un gros travail de de reconditionnement sur un lac a troyes . je me questionne sur l'achat eventuel .que vaut se bateau a votre avis et pourquoi lui preferer un dragonfly ?
merci pour votre aide .laurent

envoyez moi votre adresse mail pour que nous prenions contact merci J.L D
jldidailler@lasagesse.mfiv.fr

Hello, I've read with some concern about issues with the centerboard downhaul jamming when a boat is repeatedly grounding at a low tide mooring. I'm thinking about buying a 920 that would be kept at a dock that rests on a mud flat 2 hours out of every 6.

The boat would face up a slight grade, generally flat but lumpy, all soft mud as I'll clear any rocks large enough to see. The boat would almost certainly sink into the mud a bit. I would intend to keep it folded at the dock but could keep it unfolded if necessary (for example, if uneven loads on the floats when folded would stress the beams).

Would this creates problems for the centerboard or any other component? I don't mind if it wears the bottom paint prematurely.

Thanks very much for you help,
Dave

DaveP wrote:Hello, I've read with some concern about issues with the centerboard downhaul jamming when a boat is repeatedly grounding at a low tide mooring. I'm thinking about buying a 920 that would be kept at a dock that rests on a mud flat 2 hours out of every 6.

The boat would face up a slight grade, generally flat but lumpy, all soft mud as I'll clear any rocks large enough to see. The boat would almost certainly sink into the mud a bit. I would intend to keep it folded at the dock but could keep it unfolded if necessary (for example, if uneven loads on the floats when folded would stress the beams).

Would this creates problems for the centerboard or any other component? I don't mind if it wears the bottom paint prematurely.

Thanks very much for you help,
Dave

I think you would be unhappy in that location. Do buy the boat, but find a better spot to keep it. The reason for keeping it unfolded in the slip is for stability. Strong crosswinds (e.g. from a thunderstorm) or waves from the side could possibly topple a folded boat unless you use the halyards as guy lines to the dock. (As I recall, Quorning once quoted 45 knots as maximum crosswind for a folded 920.) Also, constant drying out could damage your bottom: Point-loads from a rock or debris, a clam or rock jammed in the centerboard slot, or forgetting to raise the rudder/centerboard could all become issues.

Hi Larry (and anyone else),
I really appreciate your reply. Let's say for the sake of argument that there is no other place to keep the boat. That if I can't keep it there, I won't be buying the boat. And let's say I clear all the rocks and am diligent about raising both the rudder and centerboard.

The reason is that the dock is at my house and I've lived there 25 years and can clear the rocks from alongside the dock and will unfold the boat if there are high winds predicted. The extraordinary convenience of keeping the boat at my house outweighs the choice of boat (it absolutely does). Will I run into so many issues that I shouldn't keep the boat there? Specifically will I always be jamming the centerboard lines?
Thanks,
Dave

I doubt jamming would be a constant issue. But it might happen. Would it be possible to set a mooring nearby in deeper water and keep a dinghy at your dock? If so, that would be a better solution.

Double Horizon wrote:I doubt jamming would be a constant issue. But it might happen. Would it be possible to set a mooring nearby in deeper water and keep a dinghy at your dock? If so, that would be a better solution.

Believe me, if there was an alternative, I'd use it. I'm on a creek that goes dry every 6 hours. At low tide, it's like the bottom of a narrow canyon with no wind and no waves, and the dock is right at my house so I can always unfold the boat in an emergency. Or always leave it unfolded-that is fine too.

Only concern is whether repeatedly settling into soft mud will damage the boat or jam the board. I'm really diligent about checklists, will NEVER leave board down or rudder down. 25 years on this creek and never left the outboard down on my skiff (which would have broken its mount). There is no deep water anywhere near by and moorings in the river have an 18 year waiting list. I would be summarily executed by the conservation commission if I put my own mooring in the river without approval. Either I keep the boat at the dock or have no boat at all. There is no dock near mine, so width (unfolding the boat) is not a problem, only an inconvenience.

Thanks, Larry!!! The 920 looks like such a great boat for me. I hope I can make it work.

In a tidal creek, you'll find the 920 is also quite maneuverable. There is (or should be) a linkage between the outboard motor handle and tiller, so the outboard turns when the rudder does. The amas draw only a few inches of water.

Feels like hiring an excavator to deepen the bottom could be a good investment

EarthBM wrote:Feels like hiring an excavator to deepen the bottom could be a good investment

From what I've heard the excavator would be the least of his expenses by the time he hires consultants to do an environmental impact statement and gets approval to dredge from local, state and federal officials?

If there's a way to make the proposed spot narrower, the creek will evenutally AUTOMATICALLY get deeper all by itself.

The movement of the water will accelerate in a narrow spot, thereby slowly dredging the bottom to try to even out the flow velocity.

I used to live on a slow, artificially dredged river which had Army Corp installed rock banks.
The designed depth was 7 feet with a pretty constant width.
At our house, there was a creek which emptied at a right angle on the river's upstream end of our property.
We had a sandy beach from the creek which narrowed the river by almost half as soon as the beach was covered with a couple feet of water.
Boaters used to go aground often, but near the other side of the river, it was 12 feet deep.
Both up and downstream from our place, it resumed the 7 foot depth all by itself, but the cross sectional area of the river was pretty constant.