Building a Glass Bottom Boat

[Lakegeezer]

Looking for experience or ideas about how to build a small glass bottom boat. The goal is more effective weed watching for milfoil. The thinking so far is to find a junker 14' rowboat or large bottom kayak/canoe, cut a hole and use marine bonding caulk to add a Plexiglas plate over the bottom of the hole. I'm a bit concerned how scratches in the Plexiglas will reduce visibility, but would rather not work with plate glass. What would you do?

[fpartri497]

Take up scuba diving Instead

[tummyman]

When I was a kid MANY years ago, my dad took me to a friends house on Cape Cod where they fined for those succulent Cape scallops. They had a very unique process in shallow waters. They had a small wooden frame glass bottom cage that they placed over the edge of a boat on the water. It used real glass on the bottom. It was sealed on the bottom wood sides to prevent water from entering, and it had a heavy fabric covering on the sides and back to help control sun exposure. Think of it this way...maybe 18 inches by 24 inches at the bottom, then a height of maybe 18 inches in the back, and then angular sides. So you stick your head in the open side, and it was amazing at how good the view was of the entire bottom. We fished with nets all day for the scallops. It was a terrific and simple design. I would guess you could build one in less than an hour with scrap wood...all you need is an old window frame with glass and some old canvas...the darker the color the better to keep out light at the surface. Might be just what you need and avoids problems with bottom of boats, etc.

[ishoot308]

Originally Posted by Lakegeezer

Looking for experience or ideas about how to build a small glass bottom boat. The goal is more effective weed watching for milfoil. The thinking so far is to find a junker 14' rowboat or large bottom kayak/canoe, cut a hole and use marine bonding caulk to add a Plexiglas plate over the bottom of the hole. I'm a bit concerned how scratches in the Plexiglas will reduce visibility, but would rather not work with plate glass. What would you do?

I would recommend using a piece of 1 1/16" tempered laminated glass for your window. Basically 2 pieces of 1/2 tempered laminated together.

Dan

[HomeWood]

Depends on how you will take it in and out of the water. If you drag it, plexi will scratch easy and likely crack anyway. If you have a dolly of sorts to put it in from your landing, I'd just go plexi. It's lighter, can get it anywhere, and easy to work with.

Maybe add some wooden or aluminum runners to the bottom of the boat so the plexi or glass is kept off the ground. Then you can drag it around without scratching it up.

[NoBozo]

Tummyman has the right idea. Either hang the box over the side..OR build it into the bottom of an old Plywood boat. Remember the old glass plate cameras they used during the Cival War..? The photographer had a black cloth over the camera and his head to Exclude outside light. NB

[SteveA]

This is interesting!

http://www.glen-l.com/designs/special/glassbottom.html

http://www.boatdesigns.com/9-6-Glass.../products/905/

and then this for only $1500! LOL

http://www.hammacher.com/Product/Def...2&refsku=10343

[John A. Birdsall]

My grandfather wanted to look at the bottom of the lake and he made this box with a glass bottom to it, and hanged it over the stern of the rowboat. We found an outboard motor on the bottom of the lake, and it was not expensive to make.

[ApS]

Originally Posted by ishoot308

I would recommend using a piece of 1 1/16" tempered laminated glass for your window. Basically 2 pieces of 1/2 tempered laminated together.

Dan

Speaking of making your glass window "bulletproof", why not use the polycarbonate used for "bulletproof glass". What I've seen is tinted, but maybe there's a very light tint available. (Polycarbonate is not costly in small sizes).

Mounted inboard, thin Plexiglass might bend slightly from the pressure of the water, but that effect could usefully magnify what you're seeking.

Alternatively, sealed ports are made for sail- and motor-cruisers. You could install one (or more) in the bottom of a $300 used aluminum canoe, but keep that black cloth handy.

(Add an electric trolling motor and bracket accessible from your position--like my own aluminum canoe--and make the middle thwart removable with four of these pins for easier access).


Try to work the shaded areas--it's going to be HOT!

[Blazen]

I actually built a glass bottom boat for a friend recently. she had an old 10ft aluminum row boat. I cut a 2 foot by 3 foot hole in the floor but left the supports and keel. I used a 1/4 inch thick piece of lexan (that bullet proof plexi glass). all I did to mount the glass in the bottom was use 100 percent silicone and drilled lots (about 100) holes all around the edge of the lexan and hull. I than used fully sealed rivets (normal rivets have a hole through them) to hold it all together. Its been about 2 years now and it still does not leak.

Honestly though if you wait till the water is flat calm (looks like glass) you can see much better into the water and in a much bigger area than you ever could through a small hole in a boat floor.

[Lakegeezer]

Originally Posted by Blazen

I actually built a glass bottom boat for a friend recently. she had an old 10ft aluminum row boat. I cut a 2 foot by 3 foot hole in the floor but left the supports and keel. I used a 1/4 inch thick piece of lexan (that bullet proof plexi glass). all I did to mount the glass in the bottom was use 100 percent silicone and drilled lots (about 100) holes all around the edge of the lexan and hull. I than used fully sealed rivets (normal rivets have a hole through them) to hold it all together. Its been about 2 years now and it still does not leak.

Honestly though if you wait till the water is flat calm (looks like glass) you can see much better into the water and in a much bigger area than you ever could through a small hole in a boat floor.

Thanks. Most of the milfoil search is done by looking down on calm mornings, using polaroid glasses. That works pretty good down to maybe 10 feet, but there are huge fields of milfoil that are deeper than that. Finding them is the problem. We have used a small tube that is also used for Secchi disk work, but the field of vision is very narrow. I wish my toy budget allowed for an underwater camera. Snorkeling works better, but it is hard to cover a lot of area that way.

You should see the quantity of milfoil being brought up. Just this Monday, the crew harvested over 400 gallons, with over 1500 "root balls". The finders need to stay ahead of the harvesters.

[dave603]

Cheap enough to make a few of them.
http://www.tropicalboating.com/2008/...-bottom-bucket