Anyone have a tri-fin, and take out the side fins and use blankers?

I don't have any for my Pocket.... and can really feel the drag...... so do most people use blankers, or just put up with a little slower speed?

Thinking I might need these? http://www.shq.com.au/products/k4-fin-box-blankers

Was just talking about this with some other Pocket owners, we all run them as thrusters at the Mo.

Can you really feel the difference ?

Looks like I better get some

You reckon or you know? I honestly reckon it's the placebo effect at best. I've sailed my quad as a twin a few times, IE massive exposed slots each side, it felt like it had less drag. IE the loss of the fins > any small drag increase from the slots.

CJW said..
You reckon or you know? I honestly reckon it's the placebo effect at best. I've sailed my quad as a twin a few times, IE massive exposed slots each side, it felt like it had less drag. IE the loss of the fins > any small drag increase from the slots.

I think that says more about straight-ahead fins than it does the blankers. Side fins need toe in.

I agree with "tape it up and see", if you can feel the difference then buy blankers.
But needs to be quality cloth reinforced gaffa or sail tape. So-called waterproof duct tape (the stuff that is like insulation tape but wider - vinyl...?) still falls off after 5mins and the half - removed tape flapping around makes for interesting moments lol

CJW said..
Which was exactly my point...How can you notice an increase in drag, as mentioned in the first post, when you remove the side fins? As you say they have toe in (same on a quad) so personally the removal of that drag will far outweigh any potential drag gains from the open slots.

I'm also not convinced that blind tested back to back someone could really tell the difference between open/covered, particularly in the waves.

Hmmm I know what u r saying but I think open slot is a bit more drag than fins. ....I guess. I meant if your fins are steup right then removing them will increase drag due to open slots.

meh, tape is cheaper than blankers, and if you can find 8mm thick nylon (cutting board?) you can make them yourself :)

(BTW if anyone knows of an 8mm nylon cutting board..... all I can find is 6 or 10mm ... let me know)

^^^ Given that a good nick in a fin can give a rough surface for bubbles to nucleate and cause cavitation (and thus spin out) I reckon TWO 8mm x 150mm holes in the bottom of the board may cause just a bit of interference to flow, and cause just a bit of looseness.

$50 says that if you are sailing an already loose board on the edge of control, you can REALLY feel a big slot in the board that is not filled.
Else racing boats, waterskiers, surfers, etc etc are all very wrong.



BTW Mr Pisstaker it was 300g paint and the ability to add a whole extra layer of material (100g) and still have a net weight saving.

Here's mine, $5 for a pack of 3 gym mats from Kmart. Never lost one yet, they are light and easy to make and replace if lost or damaged. Just cut with a blade and poke them in your empty slots, they come out easily with assistance from a screw driver. As for if you need them??? I've sailed with and without but honestly can't tell any noticeable difference...if any drag on the board it's going caused by me.

CJW said..
You reckon or you know? I honestly reckon it's the placebo effect at best. I've sailed my quad as a twin a few times, IE massive exposed slots each side, it felt like it had less drag. IE the loss of the fins > any small drag increase from the slots.

I noticed more drag (subplanning) without the side fins.... but once planning I can't say.....

Now... this is a bit different way of looking at it I suppose, but I just gave it some thought visualising the board travelling through water, then you have two cavities where water rises up into the box then hits a small wall...... just play the model through your mind... surely there is some performance lag in speed? Am I going in a race no, Am I a pro - no, but I just like having my gear setup to work well... like anyone else....

Increase the model size in your mind with a boat.... do you think it would slow a boat down?

If filling the holes gets you on the plane a little quicker... and staying on the plane in marginal winds..... I'll do it.....

Those mats are a great idea!