glass bottoms?

[John Blazy]

This forum is awesome so far - lotsa good info, sharp folks. I planned to register and post later after my new boat had progressed further, but curiosity got the best of me. My question is a little loaded, and I plan to give away my answer/method after awhile, but want to know what the existing bias may be, and will take no offense at negative views (might learn something):

Why aren't there any glass bottom boats out there? Besides some of the obvious issues like leak and breakage potential , has anyone successfully installed homemade viewing windows in their boat?
After the incredible fun and "scientific research of marine life" , in my first glass bottom boat I am amazed that I don't see more. My hunch is that the word 'glass' throws people off.
Anyway, here is a pic of a wreck site to tantalize.

[John Blazy]

Gotta try this image post one more time: <http://www.pbase.com/image/6501697>

and if that doesn't work, then I'll be giving away my ideas sooner than later at http://www.pbase.com/dr_dichro and click on electric boat construction.

thanks for your patience and input.

[Tomcat]

A window has been done a fair bit. You might write the epoxyworks editor at WEST, and ask for a free backcopy of the magazine in which Watson installed a window in the bottom of his Micro sharpie.

The email would be something like: epoxyworks@gougeon.com, it's on their site.

[On Vacation]

Welcome and I really didn't see anything that you were doing that was death defying to me.

[Bruce Hooke]

I tried it once in a fiberglass dinghy and it seemed to work well (I used a pretty low-tech approach and I didn't have any problems with leaking) but I didn't get much chance to use it because a few days later I lost the dinghy in rough weather. I'm not sure what you mean by your answer/method, but if you are suggesting that some specialized technique is necessary to get it to work, that certainly wasn't my experience. If I remember correctly, I just bolted down some lexan with some sealant between the lexan and the hull.

I can give you one reason why it is not more popular -- take the East Coast of North America as an example -- aside from the southern tip of Florida the water is for the most part so murky that anything more than a few feet down is pretty fuzzy or not visible at all! I've seen plenty of places where the bottom was not visible at all in more than two feet of water. Another factor may be that most people just are not that interested in cruising slowly in shallow water to look at what's underwater, which is too bad because there are lots of cool plants and animals down there.

[John of Phoenix]

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: fixed;"> So far [the boat's] named Larry and Bob after the inspector's names grade stamped onto the plywood I'm using. </pre>[/QUOTE]Very

Welcome and keep us posted.

[NormMessinger]

I don't remember glass in the context you use it having come up here before. It is glass as in fibreglass in epoxy that causes some of us heart burn. What you've done is a neat trick for clear water areas.

[steve sparhawk]

The only heartburn I get is from eating too much of Sue's chili and going right to bed.(with ---)You know that I have no qualms about mixing my mateerials. If it wasn't for ---------, Most of my wood would be at the bottom. (Sue knows I'm quick and you know I'm dirty)

[ 01-06-2003, 10:53 PM: Message edited by: steve sparhawk ]

[John Blazy]

You guys are good! I knew someone has at least given it a shot, and Bruce appeared to be right on with the most obvious reason why you don't see many glass bottoms - Murky water, which is exactly the case where I live in Ohio. But go up north to northern Michigan, and most lakes and epecially lake michigan around the islands and you can see bottom at thirty feet - no kidding. I vacation in these waters every summer, and that was the inspiration for doing the glass bottoms of my boats. Many wreck sites to see, as well as fish and old docks. The "trick" I referred to earlier is using Lexan polycarbonate with a scratch resistant coating. Called MR-10 sheet, it is perfect for viewing bottoms. See my site for seal details at http://www.pbase.com/dr_dichro and click on 'electric boat construction'.
The other reason I was wondering why I didn't see more viewing bottoms/portholes is based on the fact that there are other areas in the US and Canada that have clear waters like the Crystal river near Tampa, South FL as mentioned earlier, and many lakes in Canada and the Northern US.

I feel that if builders like you all knew how easy it is to install high - performance viewing windows with the (relatively) new Lexan MR-10, than many more besides myself (and all my friends that love to swim under my boat and get videotaped acting like fish underwater) would begin to enjoy this whole new aquatic world. You could call your boat a "research vessel" like the michigan DNR guys called mine [img]smile.gif[/img] .

I also thought that high-speed planing hulls would be a deterrant also, but 1/4" or greater Lexan installed in an oval shape (no stress corners) near the bow, could be installed by specialists like yourselves easy enough to handle the stress of waves (flush mount with backing plates and buildup cleats to the interior).

A little info on MR-10 sheet:
acids and solvents won't touch it, not even MEK. AR (abrasion resistant) coating on both sides is quite good (wiping mine with a sandy towel didn't hurt as much as I thought it would). This coating needs to be sanded/milled off at seal areas of course. You can get it at most plastics distributors, and cuttoffs shouldn't cost that much as it is around six bucks psf in full sheet size.

Anyone know of other areas of the US with clear waters?
I am planning a trip to visit friends in Tampa this spring (easy deadline - not) with my new boat to view the manitees on the crystal river, so I imagine there might be other spring fed waters in the US? If lived near the tropics, I'd be all over glass bottoms with Lexan.

- JB

[Tar Devil]

A forum member named Bradley built a flat bottom skiff with a glass bottom he uses offshore. Here's his website...

www.loveofsea.com

Later,

Phil

[John Blazy]

Great link. Small window, but perfect for his photography. Serious boat too. Thanks for all the info and I'll look up the epoxyworks lead too. - JB

[Bruce Hooke]

As far as other good places for glass bottomed boats goes, some that come to mind are:

1. The Florida Keys - Coral reefs are, of course, wonderful places for glass bottomed boats. That said, my preference in the keys is to get right into the water and snorkel.

2. The Buffalo River in NW Arkansas is a wonderful spring feed river with beautiful limestone bluffs and crystal clear water. It is a great place for canoeing and it is also popular for fishing. The upper reaches include some fairly serious whitewater (class III-IV if I remember correctly), but the lower reaches are quieter (mostly class I). It is a National River (part of the National Park System) so there are no houses and very few roads near the river. The best time to go, in my opinion, is in late March and early April, when the locals think it is still too cold out so the crowds of summer haven't showed up. By late summer much of it is too shallow for any but the shallowest of boats.

3. I have seen surprising clear water along the Maine coast at times but it is very variable. The trick, as well, with Maine is that you can be 200' from shore and in 100' of water and you can also be in 10' of water and run into a boulder that is 1' below the surface, but there are plenty of shallow areas where there is interesting stuff to see if you are careful.

- Bruce

[ion barnes]

I saw a dinghy with a handhole in the bottom so the owner could put a security chain through and when he went to use it, he just screwed in the cover which just happened to be clear! Ergo the porthole.

[AngWood]

So much of Louisiana's water is murky, but there are swamps and marshes where natural filtration makes it quite clear. Those clear, shallow waters are bursting with life, too--gators, frogs, bream, gar, snakes, etc.

So it's got me thinking, that and Calypsee's obvious success. A simple, easily driven skiff with a coupla Lexan viewports and a trolling motor. A canvas dodger/spray hood at the bow, maybe a canopy. I'm realizing my restoration project is one of those "long-term" things that can sit on the back burner a while. So it's got me thinking. Okay, so it's got me cutting wood and making room in the garage even though there isn't any.

[John Blazy]

HOLY DRY SNORKELING BATMAN!! I believe I may have found my first WBF convert to glass bottoms! Its easy to convert friends who've actually been ON my boat and seen the fish and marine life through my windows, but geez its been almost two years and this is the first serious consideration to glass bottoms.

Good for you, and I'm glad I saw your post. Don't let me pressure you into following through, but you've certainly stated interest, and the right philosophy: Make an easy-build simple boat, put a window in it, and get on the water - Lots of wildlife to see.

After installing my fourth Lexan window and no leaks, even with the pressure of six adults, I have yet to be bored with looking through them.

I, too have found many areas in Ohio that have crystal clear water, like rivers and inland lakes with shallows. The bayous sound awfully pregnant with wildlife - so tell me if or when you get the boat built with its windows, and POST PICTURES.

Here are a few pics of my windows:





In case that last pic doesn't go through - see my other photo site for sealing diagrams and step-by-step methods to install glass-bottom windows - click on 'boat construction'

[AngWood]

Awesome. I've looked at your website and plan on gleaning quite a bit of info from it. You've got not only a glass-bottom convert, but also an electric-power convert. I've got a stem, transom, mold, and hull sides of a 15' one-station plywood skiff sitting in the garage already. It'll be a hull before long. Then on to decking, seats, and (gasp!) cutting big holes in the bottom.

[John Blazy]

I'm glad you're an electric power convert too - I seemed to have cracked a rather elusive code that has plagued the electric power boat world (e-boat forum, et al), so carefully consider the following:

Based on years of research, I've discovered that there is a great chasm in the electric primary power propulsion world - the chasm between super cheap trolling motors (less than 500-600 bucks) and the permanent magnet motors (2 grand and wayy way up to 6 grand).

The problem with the trolling motor is that the props are all low pitch (4")- designed to push a heavy boat with quick response, kindof like driving in first gear only. So many simply shoot for the Briggs E-tek or its equivalants and pay through the nose for fittings, or complete systems, and consequently, electric drive dreams are dashed and never get on the water.

This has been solved, thanks to a couple guys on the e-boat forum, and my kort nozzle fabrication. One guy suggested using the stainless steel E-drive prop (6-3/4" pitch) from the Minn Kota E-drive motor (close to three grand) and fitting it onto the lower cost, 36 V, 101 lb thrust MK Riptide.

He ran two 101's in tandem, which didn't torque the motor that much, which is why he got away with it without burning out the motors.

I decided to put the stainless E-drive prop on my 24V 65 lb MK Maxxum, and used the kort nozzle to decrease the torque on the motor. I now easily get the equivalent of over 100 lbs of thrust with the new prop, and hit hull speed at less than full power for a 14 foot boat.

Extrapolating from this experience, less than a grand will easily power a 20 footer with the same performance that three to six grand got you before with the higher power perm. magnet motors. And a lot less hassle - way easier through-hull fittings if you choose, or you can simply transom mount.

[WindHawk]

I happen to have an 8x10 viewing port on the bottom of my yawl, and have had no leak issues (as yet). I have mixed feelings about it; however, the boat was built by a professional, and it hasn't leaked in 12 years. It does get extra attention when refinishing the bottom.

I intend to keep her forever; so, resale issues are not a problem, but imagine trying to convinve someone that they won't be having any problems with the hole in the bottom of the boat.

I asked the builder why on Earth he put it in, and he only chuckled, and said it was something he'd always wanted to do. It can be fun, but I've given some cursory thought on patching it.

[John Blazy]

I guess a window is only fun if you have clear water, and interesting things to see. You ever go to Higgins Lake with it? Super clear water, so I hear. I suppose that if the boat were small, it would be more fun. Is the window glass or plastic? I would be afraid of glass, unless it were laminated and tempered. I saw an old glass-bottom boat article from 1972, and they used windows from a '49 pontiac. Only tempered, I assume, and one rock hit, and your in Davey Jones Locker.