Boat Diver Question?

[ausaviator]

Thanks hello, that makes sense. I've only done an intro dive which was in Hawaii down to 40 ft, but little experience otherwise. Personally didn't think much of the risks of doing it to a few feet. Saw a guy doing it the other day on an air hose from a supply on the doc. Didn't actually see what the supply was.

[hellosailor]

Gah-
The weekeewahci mermaids don't get any special training. You're right, it is bs you see on tv. They're really aliens from the Roswell crash, and they pretend to suck on the air hoses so people don't come try to take them away.

[a64pilot]

The first ten feet of depth is more dangerous than any other ten feet, reason is the pressure difference is greater. Example if you dive to 33 ft., you double the pressure to two ATM, to double again requires a depth of 99 feet if I do the math correctly.
You can ascend safely from pretty deep without fear of an embolism if you simply breathe out while ascending, neat thing is you won't run out of air as it's constantly expanding, unless of course you let too much out. It's the expansion of course that is dangerous, you don't have nerves in your lungs apparently that would give off pain telling you your going to burst your lungs. It's simple really, just keep breathing while ascending, and ascend slowly, don't hold your breath and pop to the surface. You can descend rapidly though without fear.
People will argue against this, but all that is needed for an air supply for cleaning bottoms is a cheap oilless air compressor, one that will supply 2 cu ft a min. at 100 PSI is more than enough, you can do the Mermaid thing, but a second stage and mask is easier

[hellosailor]

"Example if you dive to 33 ft., you double the pressure to two ATM, to double again requires a depth of 99 feet if I do the math correctly."
The math can get futzed depending on whether you look at absolute psi, or psi over ambient. At the surface you are at "zero" psi over ambient, but you are at "one" ambient pressure. At 33 feet underwater you now have one extra atmosphere of pressure--or, two atmospheres of pressure. Every 33 feet adds another atmosphere of pressure, add and call them as you please.

But even descending can be dangerous. Have you ever had a cavity filled in a tooth? Or an abcess? You can get "tooth squeeze" as higher pressure air tries to fill into a void in a tooth. Or sinus squeeze, if your sinuses aren't clear. Same for the ears and esutacheon tubes. It is possible to get sudden stabbing pains from any 'hollow' area when you are descending OR ascending and get in trouble. I don't know if it is urban myth but supposedly if you get a tooth squeeze and high pressure air bleeds into a void? It can explode if you surface too rapidly. Another unpleasant surprise, which could cause a sudden intake of water and drowning.

But again that doesn't making diving dangerous, every certification course theoretically goes over these issues, how to anticipate them and deal with them.

Folks who have trouble remembering how to walk and chew gum at the same time, really should stay in the glass-bottom boat. The view's pretty good, and the margueritas taste better too.

[fstbttms]

Originally Posted by gah964

Hi all anyone ever hear of this called a boat diver today and this is what they said.

they want $100 hr to clean my boat 30ft sailboat they said it may take them 4 hrs and they don't scrape any paint at all of the bottom.
I asked them how they did that, they said, they take their time and have special barnacle removing tools.

Sounds crazy to me what do you all think?

4 hours and $400 to clean a 30' sailboat is pretty insane, regardless of the condition of the boat. A 30' boat that is not unduly foul should not take more than 30-40 minutes to clean and zinc. And if it's foul enough to take more than an hour to clean it, saving the undoubtably already useless paint is not really a concern. What the dive service may be telling you is they hope you go elsewhere, suspecting that your boat's bottom is a real nightmare. And failing that, they want to be very well paid if they end up doing it. In any event, I suggest you keep looking.

[Helios]

Let me check my fast bottoms invoice. Correction $2.25 per foot...
Thanks Matt!

[fstbttms]

Originally Posted by Helios

Let me check my fast bottoms invoice. Correction $2.25 per foot...
Thanks Matt!

[poiu]

Originally Posted by hellosailor

But even descending can be dangerous. Have you ever had a cavity filled in a tooth? Or an abcess? You can get "tooth squeeze" as higher pressure air tries to fill into a void in a tooth. Or sinus squeeze, if your sinuses aren't clear. Same for the ears and esutacheon tubes. It is possible to get sudden stabbing pains from any 'hollow' area when you are descending OR ascending and get in trouble. I don't know if it is urban myth but supposedly if you get a tooth squeeze and high pressure air bleeds into a void? It can explode if you surface .

Not an urban myth in so far as it happened to me descending in a plane. Maybe the most painful thing I have suffered. Totally debilitating. Not an explosion though, more like a blow with an ice pick to the jaw. I am always on edge now when descending in a plane or when diving.

Lots of other hazards from diving of course. Once saw someone with a blown in mask and glass particles in the eye. Lots of blood. Similar pressure related problem and a failure to equalise was the cause.

[DivingOtter]

I stopped doing recreational boats for the reason that people would tell me they had it cleaned 2 months ago and I would splash to find no zincs and heavy marine growth at which point the price would increase by a lot. At that point they would cancel and bitch about me charging them for travel.. I have hydraulic hill scrubbers that I can clean a cargo ship with all the way to small a machine called a Cavi Blaster that uses bubbles and low pressure to remove growth. I basically stopped because for all the gear and insurance people would try to haggle me down or " this other diver said he will charge XYZ ". Rules have changed, insurance has gone up and quite frankly I it wasn't worth the headache of owners ( not all but most in my area ) complaining that in South Florida they are cleaned cheaper. Okay true but this is New Jersey in the fall or spring so call someone else who's stupid enough to haggle. Oh , don't forget marinas in my area charge 30 % for working in the water EVEN IF THE MARINA CALLED ME.. Apparently they don't like losing out on a shorthaul.

[tomfl]

Originally Posted by gah964

Hi all anyone ever hear of this called a boat diver today and this is what they said.

they want $100 hr to clean my boat 30ft sailboat they said it may take them 4 hrs and they don't scrape any paint at all of the bottom.
I asked them how they did that, they said, they take their time and have special barnacle removing tools.

Sounds crazy to me what do you all think?

Think fastbottoms may be right about the estimate being shorthand for them wanting you to go somewhere else.

In Boot Key there are several divers that get on the cruisers net a couple of times a week and advertise. I pay $US75 for my 36 ft cat if I hire someone, but normally do it myself mostly because I like to see what my hulls look like on a regular basis.

I only draw three feet five inches so I get in about four feet of water over a clean sand so I can stand on the bottom. That really makes things easier. I also wear a hood and full face mask, gloves, booties, and full thin wet suit. It is very important to not expose your skin to the brine shrimp and other small creatures that live in the growth on your hull.

[gah964]

Originally Posted by tomfl

Think fastbottoms may be right about the estimate being shorthand for them wanting you to go somewhere else.

In Boot Key there are several divers that get on the cruisers net a couple of times a week and advertise. I pay $US75 for my 36 ft cat if I hire someone, but normally do it myself mostly because I like to see what my hulls look like on a regular basis.

I only draw three feet five inches so I get in about four feet of water over a clean sand so I can stand on the bottom. That really makes things easier. I also wear a hood and full face mask, gloves, booties, and full thin wet suit. It is very important to not expose your skin to the brine shrimp and other small creatures that live in the growth on your hull.

I didn't know that the brine shrimp was a danger, why is this? also I ended up pulling the boat out I gave up finding a diver or flake divers here.
also the barnacles just about fell off the hull.so I really don't see what all the fuss was about.

[onestepcsy37]

Good move, gah964. If the bottom was that bad it almost certainly needed to be painted. In water scraping would just be throwing good money after bad...

Sent from my GT-P3113 using Cruisers Sailing Forum mobile app

[fstbttms]

Originally Posted by gah964

I didn't know that the brine shrimp was a danger, why is this?

It's not like they are poisonous or anything. But they can give a painful little nip to bare skin and I certainly wouldn't want them getting into my ears.

[tomfl]

Originally Posted by fstbttms

It's not like they are poisonous or anything. But they can give a painful little nip to bare skin and I certainly wouldn't want them getting into my ears.

Brine shrimp are often so small they can get into any crevice in your body or in the hair under your arms, between your legs, or on your head. Problem is they die quickly once out of the water and tend to stink. But until they die they are some what mobile and can jump around on your body.

I am always shocked at how many of them are still on my protective clothing/wet suit after I get out of the water. I normally stand on my sugar scoop and dive head first to try and wash some of them off. But there are still hundreds of them all over the place.

[tomfl]

Originally Posted by gah964

SNIP
also the barnacles just about fell off the hull.so I really don't see what all the fuss was about.

Easy to say the barnacles just about fell off if you are standing on solid ground. It is a different story if you are floating in the water, or diving under the boat and have nothing to hold you in place when you push a tool against the hull of your boat. That is why I sail get your boat in water shallow enough to stand up to do the bottom job, it makes things much easier.