Looking for some tips for a glass bottom boat design

[Satrio12]

Hello everybody i am quite new to the world of marine engineering. I am currently making a paper for a glass bottom boat with its main mission being for tourism (it's for a competition), hull is going to be catamaran and its length is approximately around 10-13m. Looking for some recommendation on the type of glasses i should be getting and if you have any innovations that would be interesting for this kind of ship please also write it down so my team and I can look more into it, if you also have some tips on making catamaran designs or even glass bottom boat that would be very much appreciated. Thank you in advance

 

[TANSL]

Welcome to the forum.
The type of glass is the simplest of all (polycarbonate, tempered, multilayer). The most complicated thing is to design the structure and calculate the stability after damage, a mandatory calculation for this type of boat.
Good luck with that project. I recommend that you ask for help, not just for the glass.

 

[gonzo]

I don't think a catamaran is ideal for that; the hulls are too narrow. In general they will have a flat bottom, or at leas a flat section where people can gather around the glass bottom area. The glass bottom section is boxed with bulkhead to prevent flooding in case the glass breaks or leaks, and to keep passengers from walking on it.

 

[Tops]

I got to go on this one once, big old noisy power cat.
https://pennekamppark.com/glassbottom-boat/
spirit of pennekamp - Google Search https://www.google.com/search?q=spirit+of+pennekamp

 

[TANSL]

or at leas a flat section where people can gather around the glass bottom area.

This is strictly prohibited. The public must be prevented from stepping on or coming into contact with the glass.
The glass cannot be larger than 1x1 m, so the hull of a catamaran can perfectly have glass on its bottom, perhaps not on the horizontal part but on the inclined part, which must also be completely flat.

 

[fallguy]

This is strictly prohibited. The public must be prevented from stepping on or coming into contact with the glass.
The glass cannot be larger than 1x1 m, so the hull of a catamaran can perfectly have glass on its bottom, perhaps not on the horizontal part but on the inclined part, which must also be completely flat.

I profess zero knowledge, but am quietly observing you self contradict. You suggest a window of say 3’x3’, but then people must not walk on, so this means you have people walk by the window and say 2’ walkway each side. Now, suddenly you have a 7’ wide cat hull. At 8:1 beam, this is a 60’ cat.

I’d say a cat is not ideal for glass bottom, based on your advise.

 

[Satrio12]

Thank you everybody for responding, but i cannot change that it is catamaran and the overall length. It is a team decision and i cannot change it so yeah. Regarding the glass placement itself i am a bit confused by the advises on the thread so maybe ill let the debate go down a little. Thanks for the glass material advises id look more into it.

 

[bajansailor]

As it has to be a catamaran, how about having a glass box viewing area between the hulls, rather than in the bottom of the hulls?
The whole box unit could be raised out of the water (if desired) while the vessel is underway at speed, and then lowered into the water when cruising at slow speed to enable underwater viewing.

 

[TANSL]

I profess zero knowledge, but am quietly observing you self contradict.

You are right. I have no choice but to agree with you. You and I agree on several things, and I am glad of that.
Now think of the following configuration (there may be others, of course) and excuse the simplicity of the sketch. This is not a serious project for a glass-bottomed catamaran, I am just trying to show that, with a little thought, one can conclude that, perhaps, I do not contradict myself as much as you suppose :

 

[fallguy]

@TANSL

Thank you for the clarification.

 

[gonzo]

You can use tempered/toughened glass, or acrylic. The glass is less likely to scratch but is heavier. Unfortunately, the decision was on designing a glass bottom in a catamaran, instead of a boat around a glass bottom. You could have a bottom and one side in glass with 3 sides for people viewing. Considering the narrow beam of a catamaran, viewing from 4 sides would make the glass area too small.

 

[Satrio12]

As it has to be a catamaran, how about having a glass box viewing area between the hulls, rather than in the bottom of the hulls?
The whole box unit could be raised out of the water (if desired) while the vessel is underway at speed, and then lowered into the water when cruising at slow speed to enable underwater viewing.

That sounds super interesting are there boats out there that uses this?

 

[Satrio12]

You can use tempered/toughened glass, or acrylic. The glass is less likely to scratch but is heavier. Unfortunately, the decision was on designing a glass bottom in a catamaran, instead of a boat around a glass bottom. You could have a bottom and one side in glass with 3 sides for people viewing. Considering the narrow beam of a catamaran, viewing from 4 sides would make the glass area too small.

do you think using a heavier material like tempered glass can affect the overall area of the viewing part? instead of using polycarbonate. Would also love to ask for boats with around a length of 10-15 meters and a width 4-8 meters, what size of the viewing area would be around?

 

[TANSL]

@Satrio12, the area of the glazed area has nothing to do with the type of glass used and can be as large as you like if you calculate the structure properly. This, the one of the bottom glazes areas, is a delicate subject and you should not let yourself be guided by amateurs who only know it from photos in specialist magazines.
Here is a sample in case it helps you in any way.

 

[gonzo]

A 15 meter boat with a width of 8 meters would be really beamy and not a catamaran. It is possibly a slow barge. You would need about 90cm per person on the perimeter of the viewing area. Using glass or polycarbonate would not make a difference in the overall area. The problem with polycarbonate is that the material is rather soft and scratches easily. That means that cleaning has to be done very carefully. Also, the cleaning has to be done often enough that not much marine growth accumulates. If you had a boat that is 15 x 8, and you leave 1.5 meters between the edge of the vieweng area and the hull sides it gives a width of 5 meters left for the viewing area. That means about 12 people on the ends. The length depends on how much deck area is needed for other activities.