Aluminum boat

[GMC FishHauler]

A local boat shop and some friends told me that the rivits on the bottom of my boat would produce alot of resistance in the water. Is there anyway to fix this?

Also is there anyway to make my boat float more even? The back is much lower than the front when still and i have problems leveling out when open. I was going to try and relocate the batteries to the front and fix this.

[AwShucks]

I would think any resistance formed by the rivets would be inconsequntial. Sure, they will produce drag... but everything produces drag of some sort. I would say your not going to loose enough speed to even worry about it. To check the way your boat sits in the water, put it in the water completly empty and see how it sets. It should be just about level. If the stern is setting lower, you can compensate by balancing the load. The critical dimemsion if the freeboard, or the amount of space between the top of the water and the top of the boat at its lowest point. The more freeboard there is, the safer you are. If you ever get to where it is just a few inches, you need to rethink what your loading into the boat and try to reduce the weight. Be conscious of the max weight capactiy of your boat, and don't knowingly carry more weight. You may do it accidentally and hopefully you will live through that accident.

[GMC FishHauler]

i ran into problems this weekend while me and my friend were fishing. stern was about 3" above waterline. I am not that big (190lbs) and he is pretty big(270lbs) but besides us there was only 12 gals fuel, 2 batteries, and the necessary stuff to make boat legal. I figure if i move one or both batts bow (under the front compartment) then it could help. That is almost 60lbs relocated right there.

My boat is rated for 600lbs of people and gear. I called dealership and they said that the fuel and batteries were included in boat weight not subtracted from the 600.

I normally would not be worried about stuff like this but it was kind of choppy this weekend and had to run bilge a little bit.

[FishBrew]

What size (lenght) boat? does it have any decking? What size motor? what size gas tank? Keep any water/livewell in the boat?

Don't worry about the rivets having to much drag. If they don't leak, fish on.

Normally the heaviest things in a boat ... you, motor, gas, batteries. Some can be moved, some can't.
Can weight be added to the front to offset this? Maybe ... But no matter what, like Awshucks said, don't exceed the weight limit ... be sure to count yourself and a fishing buddy in your weight calculation.

[GMC FishHauler]

What size (lenght) boat? does it have any decking? What size motor? what size gas tank? Keep any water/livewell in the boat?

Don't worry about the rivets having to much drag. If they don't leak, fish on.

Normally the heaviest things in a boat ... you, motor, gas, batteries. Some can be moved, some can't.
Can weight be added to the front to offset this? Maybe ... But no matter what, like Awshucks said, don't exceed the weight limit ... be sure to count yourself and a fishing buddy in your weight calculation.

17' bass boat style, 1/2" sealed plywood decking but this is on the front and middle, 70hp merc., (2)6gal tanks, 10 gal livewell about half full this was because of fish.

[AwShucks]

It surprises me to hear the weight of the fuel, etc. was calculated into the weight capacity. My understanding has always been that if it is something you put into the boat, you add the weight. That would include fuel and batteries. I don't think it would have squatted so low in the water if those weights were all ready calculated.

[FishBrew]

help me out a little with "bass style" with no decking in the rear ... does it have a steering wheel (console), or is it tiller style (you sit in back to steer)? Are those built in gas tanks?

[wylie catter]

Relocating those batteries will help a good bit. I don't blame you for getting a little nervous about it, 3" is not enough boat out of the water for me. I've never measured the height of my transom above the water, but it's around a foot. And I've been anchored before and had big wakes come up over the back of it.

[GMC FishHauler]

the decking on the rear is part of the aluminum that is built on the boat, it is pretty much wide flat bottom with slight V up front, looks like fiberglass bass boat but made of aluminum.

The manufacturer said that the weight of fuel and the batts. was already factored in. I was thinking that it wasnt but they said it, and i heard it. Tanks are removable.

I think alot of the problem was that too much weight from fishermen in the back half. I was in drivers seat and he was next to me in left side low seat.

I am gonna move batts and see. if it doesnt help, no big deal, i will just sit up front and use trolling motor when i get one big enuff to move boat around in the wind.

[Katmandeux]

Wow.:sad2:

Your dealer is full of it. The maximum weight capacity given on the plate is for everything added after manufacture...persons, cargo, motor(s), fuel, battery(s), etc.

Having said that, 600# sounds pretty low...but then again, freeboard doesn't lie.

[Mark J]

First I want to say the amount of freeboard you have dont mean squat.
Bouyancy is what matters.
Some of the alltime greatest hull designs for running the inlets and netting in the OCEAN have very low freeboards amidship and most of these designs were first built with oar power.


Second, with you, your buddy and the gas you are at 532 pounds and we haven't even added the weight of the gas tanks themselves, the 70 horse motor or the two batteries and other gear.
If the weight you specified for the boat is correct you are way over capacity.
I dont doubt the capacity rating at all. I had a 17 foot fiberglass bass boat with a 850 lb capacity.

Bassboats dont sit level in the water. The weight of the motor hanging off the back will see to that. You can put your batteries up front but a word of advice. You will need to increase your battery cable in size.
Your batteries wont last long either. Wet cells dont take beats and bangs like associated with the bow of a boat on wakes very well.
Gel cells will solve this problem. You can mount them on their side, upside down, or right side up and they'll take a whole lot more pounding then a wet cell.
An example of the wire sizing.
At 50 Amps you use a #6 copper for up to 5 feet which I imagine is what you currently are at.
If you increase that distance from say 9-14 feet in length you'll have to make that cable a #2 copper. # 2 fine stranded copper or (welding cable) aint cheap.
DC voltage drop is a whole different ball game then AC voltage drop.

The bow on a bass boat is not a high volume bow meaning it doesnt hold the bouyancy of say a ski boat. You got to be careful about moving weight forward in a bass boat because it could easily make broaching a problem. Broaching is when you approach a wave instead of the bow cutting or ridng up the wave, the bow will plow the wave or "submarine".

[Katmandeux]

In a jon type hull, with very little reserve buoyancy, ample freeboard is a nice thing to have, actually.

Freeboard amidships, and freeboard at the transom on a planing hull, are two very different considerations...apples and oranges.

[GMC FishHauler]

sorry, wanted to clarify something.

Tag says 4 persons or 600lbs.
1030lbs persons, motor, and gear
80hp

[GMC FishHauler]

i also want to say thanks for all the info from everyone. you guys have been huge help. I am very new to boating (4 times out on water and this weekend was the first time with waves and someone on the large side.)

[Mark J]

The bow of the boat determines how low one can go.
Today's boats are designed more for looks then function.
The sleek corvette look of boats is nothing but eye candy for a buyer and boats that sell themselves from the dealer standpoint.

The majority of people in the market for boats dont like what they would call old timey or traditional boats like the high bowed dories. They aren't as easy on the eyes as that sleek rounded out job. Well some of us like the look:smile2:

There is nothing new or innovative in hull designs from a function standpoint although some manufacturers claim they have something no other has.
The latest sales ploy I ran across was a dealer touting their stepped chines. " We invented the chine on this boat, Its a revolutionary breakthrough".
Stepped chines have been around alot longer then I have.:roll_eyes: ( I fell off the tater truck, not the turnip truck).
Its a sales market these days. Not a function market.

Here is what I'm talking about when I say the bow determines how low one can go. This boat has alot of history behind it. A rich history. Designed and built by a cabinet maker. So functional this hull design is it turned into a legacy. This low freeboard boat was built for the treacherous currents, and shoaling in the NC inlets. They were paddled and motored through the inlets for offshore fishing and netting. You've got 40k boats that are bigger that cant go where this one can.

So successful in function that a club was formed for people that either build these from scratch or restore originals. Some of the originals have wound up in other countries. They even have a yearly gathering of Simmons Seaskiff owners right close to our own Bobpaul.
Notice the low freeboard, the motorwell, and the high bow. These things were run offshore all the time in the graveyard of the atlantic.
Those high "ugly" bows are functional.

High sides dont mean safe in high seas. High sides does mean you have a built in sail though. The more profile you show the more there is for the wind to grab. The bow meets the wave before anything else. We dont drive boats sideways or motor them through storms to get to a safe port in reverse either.
If she'll track in a following sea (hard to find one of these "pretty" boats that does) and you have that "ugly" bow up front for a battering ram, you got something that is functional. It doesnt matter what the freeboard is or what she looks like. The term freeboard is used about as loose as the term deadrise by most people.
Everybody looks at the back of the boat for deadrise. The back of the boat aint breaking the wave:lol: . The deadrise at the bow is the more important of the two. There again, the functional bow deadrise is them "ugly" ones like on lobster boats.
Of course as with anything, you have the good and the bad. It helps to be a good captain.

http://www.capefearmuseum.com/simmons_skiffs.htm

[KansasKatter]

It never ceases to amaze me that people are so hung up on speed with a fishing boat, especially for catfishing. Of courst I am assuming this is the reason you are worried about drag from the rivets? The amount of drag this is causing you, and speed resulting from the drag is so minute, you will aquire more drag from a piece of mud, or a ding in your prop than the rivets of your boat.

Besides, even if you are losing speed due to this, the amount might mean you are getting to your "hole" at the most 30-45 seconds later than if no drag, and that is on a long run!:wink:

[GMC FishHauler]

not concerned as much about speed as fuel consumption (only 12 gals.)

[KansasKatter]

Gotcha! I have a 16' rivet jon, with a 25hp Mercury on it. Loaded with me (245lbs) my brother (200lbs) and all our gear, including a cooler of beer, bait, anchors, alum floor, you name it, we can buzz around all day long (and believe me we have) on 6 gallon can, and not even come close to running out of gas.

I jumped to the conclusion of the speed thing due to past posts. Seems everyone is in a hurry to get some place on the water, half the fun is getting there!:big_smile:

[oh no]

My boat is welded aluminum and had welding splatter on the bottom. I gained 15 mph by going over the bottom with a nylon buffer and removing that splatter. When I was done I coated the bottom with a product called -- Liquid Speed -- a teflon bottom paint. My boat went from 45mph to 60+ on flat water.

I can see where rivits would take away some from the smoothness of the bottom, just like that welding splatter did.

[Katmandeux]

^^^I agree, although at slower speeds, the effect will be less dramatic.

[KansasKatter]

Just curious, did you test speed before adding the undercoating, with just the splatter removed? If not, I would be willing to bet the coating is contributing to your gains WAY more than the welding splatter.

Unless of course, the welder could weld no better than me! Then you are talking about GLOBS, not splatter! :big_smile: :wink:

[GMC FishHauler]

My boat is welded aluminum and had welding splatter on the bottom. I gained 15 mph by going over the bottom with a nylon buffer and removing that splatter. When I was done I coated the bottom with a product called -- Liquid Speed -- a teflon bottom paint. My boat went from 45mph to 60+ on flat water.

I can see where rivits would take away some from the smoothness of the bottom, just like that welding splatter did.
where did u get that liquid speed

[Indigo Flats]

My 16' boat has a 20" transom. This makes it a lot safer on big water when anchored but the downside is when you have a 25HP tiller engine that has the long shaft and decide to get another engine there isn't any demand for a used long shaft, lower horsepower engine. Notwithstanding this, I would still highly recommend a boat with a 20" transom for safety's sake.

[GMC FishHauler]

if rough weather becomes too much of a problem after i try and fix some things in my boat, i will just limit where i fish according to the wind. This sucks, but cannot afford another boat right now.

[oh no]

They had that product in 2000, now they don't have it. I don't know why, I sure wish they still sold it. My boat could use another coat. That stuff evaporated fast like brake cleaner, in fact it had the same smell. I sprayed it on with an old Fantastic bottle and it looked kinda cloudy, but boy was the bottom slick. I only applied it for fuel milage purposes, not for speed. Anyway thats what I told the wife. lol lol

The first year it was on, only V8s could whip my 3 cyilnder 90 hp. lol That boat would flat cook. It would set the water on fire, just like the Merc. commercials used to say.

It was made to be used on racing sailboats, to give them an edge.

[oh no]

www.defender.com They are out of Waterford, CT. They handle all sorts of boating supplies for little boats to ships. Good outfit, lots of coatings for boats.

[KansasKatter]

I was watching Christmas Vacation last night. We need some of that crap that Clark sprayed on his sled!!

Your boat would not even touch the water then!! :big_smile:

[KansasKatter]

I do know one thing the rivets are giving my fits with is causing my depth finder to go haywire once you get moving hardly at all. There does not seem to be a place to put the transducer, without picking up bubbles from the rivets.....:confused2:

[oh no]

I see this stuff dries in 15 minutes, ready for the water. It might be the same product as Liquid Speed under a different name. I think I will try some on my boat.

[Katmandeux]

I do know one thing the rivets are giving my fits with is causing my depth finder to go haywire once you get moving hardly at all. There does not seem to be a place to put the transducer, without picking up bubbles from the rivets.....:confused2:

The more I think about this, the more I'm inclined to believe the rivets contribute a significant amount of drag. The rivets on aircraft are countersunk for a reason.

If Liquid Speed worked wonders, and is now no longer available, I'm betting it's because something better came along to take its place.

[oh no]

You might be right!!!!!!!!!!!!!

:big_smile: :big_smile: :big_smile: :big_smile:

[crazy]

Umm i think some of you are crazier then I am. I would think if this liquid speed was such hot stuff that they would not go out of business and everyone major boat company would be using it. That and telling there customers to use it. Unless it is some conspiracy by the oil manufacturers now days. So you waste more fuel. Scratch that I would think the oil company's would be using it on there oil tankers to ship the goods over here. I mean what a 33% increase in speed? If you want fuel economy you need to get up on plane so you have less drag in the water. Instead of full throttle snow plowing the water.

[Mark J]

A boat will run faster on a chop then on slick water.
With a chop you have less hull in contact with the water at any given time.

A boat with a super slick bottom is not really what you want for speed.
Its harder to break the suction on a slick surface.
The boating world is not immune to scams.

[cat tamer]

I do know one thing the rivets are giving my fits with is causing my depth finder to go haywire once you get moving hardly at all. There does not seem to be a place to put the transducer, without picking up bubbles from the rivets.....:confused2:
Jeff,
I have had the same problem with air bubbles and turbulence under the
boat interfering with the depth finder, so I switched to the vexilar alumaducer in the place of the original transducer and now I have a accurate reading even at 40 mph and a big plus is I dont have to worry about breaking off the transducer when brush comes under the boat side ways.

[three_rivers]

marks right, you'd want a rippled surface. I've talked to some guys that have blistering fast bass boats and they told me to leave my pad rippled (like it was when i got it). It creates more air between the boat and the water bringing its speed even faster.

[GMC FishHauler]

i cannot see how a rough surface is faster than smooth, and who is breaking suction?? Turn a cup upside down on wet surface, it is easy to move around. Try to pick it up and u get suction, I just wanna move my boat around i have no need to pick it up.

[KansasKatter]

The more of the boat you can "pick up" out of the water, the less contact area you have with the water, thus less drag. Simple physics :tounge_out:

The rivets of an aircraft are recessed to reduce noise, more than drag concerns.

Kirk, Do you have a link for that transducer? Are they expensive? I think Santa Clause is bringing me a new depthfinder for Christmas, just a feeling:wink: That may be a good time to swap transducers, before putting a new set of holes in the transom.:confused2:

[crazy]

Jeff www.vexilar.com is there website. Thought about getting one once before just never knew anyone that tried it. Now I guess we do know someone that has used it. Problem is the new boat I'm getting has a tunnel hull.

[cat tamer]

Cabellas carries them cheaper than you can get one direct from vexilar if they have it in stock.
I bought mine through vexilar only because cabellas did not have it in stock and I didnt want to wait.
vexilar ships very quick.

[dougc]

Josh, wouldn't you still be able to use that transducer, just move to one side or the other? You can't run it in the center anyway. Mine's mounted about halfway between the motor and the right side of transom.

[crazy]

Yeah I should be able too... they have a nice how too video for download. Just don't know about the air pockets under the boat. They say find a nice flat place with none under it.

[Clovis]

i cannot see how a rough surface is faster than smooth.

Think about it like this:

Friction is what you want the least of for speed on water.

Friction is also want you want most between your tires and the pavement in drag raceing.

Slick tires create more friction.

So does smooth water.

[GMC FishHauler]

Then why are fiberglass boats smooth at all?
should they be dimpled like golf balls?
why are submarines smooth?
When i think of perfect aerodynamics i think of a boat-tailed bullet. In target shooting the smoother the better, why doesnt this work in boats?

[GMC FishHauler]

Think about it like this:

Friction is what you want the least of for speed on water.

Friction is also want you want most between your tires and the pavement in drag raceing.

Slick tires create more friction.

So does smooth water.
the reason smooth tire have more traction(friction) is more surface to roadway.
On the bottom of my boat these rivits are creating more surface than my boat would have if it was slick bottom. I am not arguing smooth water over choppy, i am curious to how much drag the several rows of rivits are causing on my boat.

[crazy]

the reason smooth tire have more traction(friction) is more surface to roadway.
On the bottom of my boat these rivits are creating more surface than my boat would have if it was slick bottom. I am not arguing smooth water over choppy, i am curious to how much drag the several rows of rivits are causing on my boat.

Put it like this none that you can tell......

[GMC FishHauler]

Put it like this none that you can tell......
i appreciate the input, i figured that it was very slgiht drag, but ya never really know

[crazy]

Thinking about this more and more.. For the size of all the rivets on the bottom of your boat. You would probably get more drag sticking your hand in the water while you where moving.

[Mickey]

If the boat drag from rivets was a major problems the boat owners would be screaming by now and technology would have been changed. There is thousands of rivited boats on the market and this is the first time I have ever heard this question,I don't think the drag is noticeable. Just go fishing and enjoy.

[GMC FishHauler]

i only questioned because it causes enough turbulance to disturb my fishfinder and flasher.

[Willy]

Take it from a old metal mechanic, you do not want countersunk rivets in your boat. Too many bad things will happen if not done properly.What drag you are getting from buttonhead rivets will not amount to much. As far as creating bubble messing with your fishfinder best advive is to get a plastic mounting plate and use it to be able to move your transducer to the correct place without drilling a bunch of holes in your transom.

[oh no]

I think some of it has to do with weight too. Fiberglass boats weigh a lot more than alluminum. My Lowe 19' Roughneck weighs 660 pounds and my 90HP Merc weighs 330. I'm pertty light with the HP of that 90.

Most rivited boats are small ones --- fishing ones---- u dont need lots of speed. Of course I'm a polack and speed is important. Ive seen the same thoughts in hill runners too. lol lol

My boat has a flat bottom so I do not open it up in any chop as I would beat myself to death. When my boat is running at full throttle on flat water, I can adjust the tilt and trim so only about 2 feet of my boat is touching the water. With that I'm cooking about 60. In any great amount of chop my boat rarelly goes much over 35. I'll spill my beer going faster / oh I'm sorry my coffee.. LOL LOL