Skeg/turn fin

[Atious]

As I'm not going to be racing, would a skeg on each side of my Lap Cat III be to any benefit?

 

[duc]

What do you expect/need from these fins?

 

[Atious]

I thought a tunnel hull needed one for assisting turns?

 

[Ron Olson]

Today's tunnel hulls don't need them. If you can't turn it enough without them, you probably have problems elsewhere. Some newer tunnels came with them to compensate for a poor design.

 

[not2bright]

i have a lap cat 3 with a turnfin and it can turn on a dime to one side but the other side it gets tricky. i also have a lap cat 1 without a turn fin, it turns fine but not as sharp. the turn fin also creates alot of drag my opinion leave the turn fin off

 

[DALE]

I have one lapcat with a .67 on it ,my friends and i have tryed the turn fin with no success. i think it got worse don't wast your time unless you feel board one day at your pond and feel like messing with it.I no when i'm at my pond trying things is part of the fun. But don't forget now you have two holes in your boat,buy worse i mean it hooked in the corners. make some stummble blocks out of balsa wood and add a 1/8 by 1/8th piece of wood along theoutside of left sponcen looking from the boat upside down transum towards you up to the first groove 7 1/2 " long it realy helped mine beleave me i'v spent many days trying different things and it runs great. But never like my htb's good luck.

 

[dale]

Never tryed skegs but i seen them on a real tunnel boat they must do something. ??? Maybe more stable the straight away.

 

[not2bright]

you dont need stumble blocks or lead in the front. the lapcat hull is perfect from the box many people that have run this hull like it because it needs no mods and runs great in the ruf stuff

 

[Atious]

I got to learn to ask these questions BEFORE following the directions. Already have the holes drilled and blindnuts in position. I guess I'll try it with and without the skeg and see what happens. Thanks for all the replies.

 

[duc]

I know lot of lap-cats do have them (as a part of the kit maybe even?) so they can't be too bad. However if you dont need them don't put them on would I say.

I've seen a lot off real tunnels but not ever one with a skeg/fin.......

 

[DaddySundown]

A turn fin is the way to go on any of the lap cats. I have a lap cat 1 and 3 and a 32" racer they all run great with the turn fin but you do need to modify it as in thinning a sharpening the front of it. Do you have the instruction sheet that comes with the boat? If not you can get one from prather. It has alot of valuable information in it. One advantage the lap cat has over the later tunnels is that you don't have to back out of the throttle when you enter a turn to make the boat set. The lap cat will run full throttle into the turns. This is where you beat the other boats, in and out of the turns.

my 2 cents

Alan

 

[Atious]

Its already sharpened and installed. I bought it new and always keep my direction sheets.

 

[_laxmasta2039]

a turn fin on both sides.....wouldn't they counteract each other and just create a drag and stabilize the boat instead of making it turn more easily?

i though that was the reason putting two fins on a hydro wouldn't make it turn both ways? :-X

also, what's the diff between the way a skeg acts and the way a fin acts [besides looking different] ?

anyone know?

sorry Atious but your Q's created a couple of mine, you can get me back by asking additional Q's in my Q threads, dont worry there are plenty of them!! ;D

Joe

 

[Atious]

Sounds on-topic to me.

I used dual turn fins on my deep vee(prather 46) and they performed better than a center skeg did. 'Course, going to a dual rudder with no turn fins worked even better. I even tried going with 10* angled dual rudders once as a nearby lake has some tree trunks that make a real cool obstacle course. Getting the linkage to work right was a real pain though. It worked nice on slow running but straight speed suffered.

 

[_laxmasta2039]

i think it would work better on a vee because there's more contact w/ the water so the fins dont have as much impact.....with a hydro there's very little surface area touching at full speed so the fins have a huge impact on it's turning availability....a tunnel would probably be somewhere in-between?

wow, you musta been confident with your boat to run a course w/ tree trunks- a missed turn and you've traded your boat for a pile of matchsticks and some hardware!! lol, all the ponds around here that have treetrunks are full of weeds, hidden rocks, etc. so that's what im thinking of when you say "treetrunks"

Joe

 

[Atious]

It's a lake that is man made. The water by the trunks is about 5 feet deep. I was/am pretty amazed at the strength of the Prather line-up of boats. They are very strong. I've clipped the trunks on occassion only to damage the paint. The only real cost in most of my gas boats is the hull. I make all of my own hardware and my engines are picked up from the scrap piles behind lawnmower shops. Being a small engines mechanic I got my start in lawn equipment so rebuilding one comes second nature. I actually enjoy building them more than running them so losing one really wouldnt affect me as much as it would others. My new interest in nitro though is a completely different matter. I don't think I'll be finding replacement O/B's so cheaply so I'll stick to safe open waters.

 

[Slideblues]

Well I dont use them, but some do, Tommie Lee's SAW record holder:

 

[duc]

talking about negative angle............

 

[Hydroguy8234]

I am building a Dumas Atlas Van Lines U-71 (36"Pay and Pack hydro). The instructions show to mount a small turn fin on the rear of the right sponson. However my U-1 has a large fin mounted on the bottom of the right sponson. Does it matter which type I use? I would like to use the same type as my U-1. What do you think? Thanks!