Bottom Paint Question

So took the boat out Thursday for annual maintenance, will pull drive, new zincs, filters, etc, etc. Thoughts on the bottom paint: Boat sits in salt water 24-7-365. Gets bottom cleaned by divers each month. Boat was new in May, 2017 with new bottom paint. From these pics, is it time for new paint? If so, what is best for a planing boat that sits in salt. Thanks

Is the paint gone where it looks whiteish? If so you are ready for a paint job. I would use and ablative paint. It will wear away as it ages so when it is time for new paint you don’t have to sand off the old paint, just put on the new paint. I hope you had a barrier coat applied before the bottom paint was originally put on.

Yes the lighter areas is where paint is gone, but it is not gel coat white but an off white color. Wondering if that is barrier coat? What effect would barrier coat or lack of it have on the repaint?

The barrier coat doesn’t really effect the bottom paint but it will help stop the bottom from blistering. You don’t want blisters! Did you buy the boat new? If so I would ask whoever put on the bottom paint and see if they did a barrier coat. If not then before you do more bottom paint is the time to do it. The off color white paint may be a barrier coat but I would check to make sure.

Interlux makes a really good barrier coat, Interprotect 2000. You can look on their website and do more research.

Comodave, thank you will check on that tomorrow.

Yes bought it new. The Sea Ray hull warranty papers I have state that blisters are covered provided a proper barrier coat was applied. I will check with dealer tomorrow. Buying this boat was so much "fun" I can't wait to hear what the dealer tells me��.

Well, a responsible dealer would do a proper barrier coat, blistering isn’t an unknown phenomenon. Barrier coats have pretty much been standard for many many years. I would almost assume that they did one, but I would check.

With the monthly bottom scrubbing, it appears bottom painting AT LEAST is necessary for you. Don't think that's needed for most boaters.

Why are you asking here? Ask your diver.

Asking here because I don't know the answer. I've had similar boat on Lake Erie for years and never painted it. I heard this type of paint wears off but not sure when its lost the protection. Waters are so murky where I now dock in SC that you can't see much underwater so a divers opinion would likely be an estimate. I may have a combination of ablative paint bring washed too often because I can't get down to use it. That'll change come January 1st. Hello retirement ?

Mark P said:

Waters are so murky where I now dock in SC that you can't see much underwater so a divers opinion would likely be an estimate.

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Your hull cleaner is the expert and regularly sees your anti fouling paint working (or not) in real-world conditions. Why you would discount his opinion and take advice from people who have never cleaned a boat bottom in their lives is beyond me. But hey, it's your dime.

I totally agree, the diver is the expert and I am not discounting his/her expertise. What I am questioning (or discounting if you will) is whether they can see it clearly enough to give an expert opinion on what needs to be done - I am not sure he/she can given our murky waters, so why I turned to this forum ot see what others offered up. If the Marina where it is at now backs up the diver's opinion, well I will have learned something - and wifey and I have lots to learn on boats - heck I didn't even know what a barrier coat was until Comodave shared that with me in this string. I am not embarrassed by what I don't know, since it is a lot!! I will post what the marina tells me soon. Thanks all.!!

That is what the forum is for. Ask questions and someone out there usually has some answers. Everyone has to start learning and we can put our knowledge together and help everyone. Don’t hesitate to ask, we love to help and we also learn during the process.

Mark, Seeing the pics, much of the existing paint seems to have gone. If you want it antifouled you need more paint. To non expert me,the question is more whether you use ablative or hard paint type. If you need to continue scrubbing monthly, hard might be better,but this is the kind of knowledge the locals in your specific area, like your marina, will know best. Asking them, as you are, is a very good move.

Dave's comments regarding a barrier cost are spot on! Hope you find it was done. And don't forget your out drive, bonding and cathodic protection. Easy to fix, expensive if not cared for.

Mark P said:

So took the boat out Thursday for annual maintenance, will pull drive, new zincs, filters, etc, etc. Thoughts on the bottom paint: Boat sits in salt water 24-7-365. Gets bottom cleaned by divers each month. Boat was new in May, 2017 with new bottom paint. From these pics, is it time for new paint? If so, what is best for a planing boat that sits in salt. Thanks

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I've seen some of the most pathetic jobs of bottom painting provided by new boat dealers. Looks to me like you got a Marine Max special. They're not the only ones doing that. I saw one boat sold on the Chesapeake, came to FL and in less than six months no bottom paint. Dealer made all sorts of excuses but finally gave in and repainted it, right this time.

So, here's another question. When the ablative paint has become thin, opinions please on whether to apply one coat or two coats of paint. We boat on the east coast, primarily on the Chesapeake.

BandB said:

I've seen some of the most pathetic jobs of bottom painting provided by new boat dealers. Looks to me like you got a Marine Max special. They're not the only ones doing that. I saw one boat sold on the Chesapeake, came to FL and in less than six months no bottom paint. Dealer made all sorts of excuses but finally gave in and repainted it, right this time.

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Maybe a tad harsh. It`s been diver scrubbed approx. 28 times since application, as well as being in the water and getting used. If it`s ablative,I doubt it should be much better than it appears.

If it was me doing the bottom paint, I would go ahead and do 2 coats while I was at it and had everything setup to do the job. It won’t hurt to do 2 coats it will just last twice as long.

Two coats if not 3 here. No idea of Chesapeake conditions, but 2 coats is minimum imo.

BruceK said:

Maybe a tad harsh. It`s been diver scrubbed approx. 28 times since application, as well as being in the water and getting used. If it`s ablative,I doubt it should be much better than it appears.

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Could be on this case, but from what I've seen too often, this may be the exception. Cleaning once a month should never involve scrubbing. Now, running it a lot in that time, it could just be beyond it's life. Still, looks exceptionally bad.

Ablative in his location is also a choice of debate.

well the paint is gone, if it was ablative that's the reason, if the diver used a scrubbing pad that was too course that an issue.


Did the diver tell you months ago he sees spots with no paint?


If so you should have pulled it then.



I suggest not using black it's hard for the diver to see things.


For a few years ago I used vivid white at that time I did my own bottom every week or two due to racing the visibility was great can't miss anything. But that was ablative, 6 months paint gone. But in NY that was about the whole season.

My current boat in FL was black when I bought it, now a light blue hard bottom paint.

THe barrier coat usually will remain in tact just bottom paint will wear away


sand it down, call the paint manufacturers ask their opinion for your area, paint two coats three on the water line.

Jamestown Distributors runs a bottom paint survey every year and publishes an interactive map to help you choose a good paint for your specific location.

https://www.jamestowndistributors.com/userportal/surveyMap.do?surveyId=101

I tried Total Boat Spartan bottom paint on my stern thruster for a test to see how it worked. Put it on exactly per directions and applied 2 coats. We store the boat in a barn for 6 months out of the year. After 2 seasons which is equal to 1 year the paint was completely gone. Very disappointing. I will be using Micron when I paint the whole bottom next time.

Bottom Pait Question

You might consider a Hydrohoist or other device that keeps the boat out of the water when not being used. We had one for our SeaRay, I think it paid for itself within a couple of years....

We use Trinidad XL, advertised as being good for 5 years. Our trawler had been in the water for 3 years since last haul out, diver goes down once every two months, says it looks like new. Last time we hauled out after three years bottom paint was in good condition. It's a little pricey, runs between $280 and $300/gal but saves frequent haul out fees.

Two coats, maybe three? Yes but why? Are those who apply multiple coats leaving their boat in the water all year? Having their bottoms professionally cleaned? Are they concerned with paint build up over the years? Are they using the right paint to begin with?

If users are applying ablative paint with more than a single coat I believe they are circumventing the main feature of ablative paint which is design to wear away. Maybe they should consider using a hard bottom paint instead. I avoid putting more paint on our boat than required to get through a single 5-6 month season. Paint buildup becomes a BPITA after years of over painting.

I was pleased with our boat’s bottom condition when it was hauled last week. Last spring I applied a single coat of West Marine’s Hydrocoat ablative paint. Starboard bottom side still has plenty of paint left and I will not put more on it for next season while the port side is substantially worn off. That side will be repainted prior to spring launch. My paint worn side is a good example of ablative doing what it is designed to do!

With ablative paint you can put more than one coat without any problems. If you put more coats it will just mean that you can go longer between painting. Ablative paint will just wear away with time. It shouldn’t build up thickness if you aren’t painting too often. If you paint the first coat a different color and then subsequent coats the final color, when the first color starts to show through it is time to repaint.

I'm going to clarify a number of erroneous assumptions being put forth in this thread:

1.- Regardless of how frequently your diver cleans your boat bottom, the media he uses to do it is 100% predicated upon the fouling he finds when he gets there. A statement like, "If you have your boat dived monthly, the diver should never use a scrub pad" is patently ridiculous. If your paint has outlived its useful lifespan and is fouling badly , that fouling may very well require an abrasive pad to remove it, regardless of paint type or cleaning frequency.

2.- All anti fouling paint manufacturers (and this hull diver) recommend a minimum of two coats of paint with three at the high wear areas like the waterline and leading/trailing edges of appendages. Boatyards are notorious for recommending just one coat because they know that with less biocide on the hull, the sooner you will need to haul for new paint.

3.- Anti fouling paints work (ablatives included) at least in part by leaching their biocide into the water very near the boat hull. For this to happen, water must penetrate the paint's surface. Yes, it is possible to apply so much paint that the water cannot penetrate the paint matrix deeply enough to free all of the biocide and in this case, the additional paint is useless. But two or three coats of any anti fouling paint are not enough to cause this. And again, when you apply a single coat as opposed to two or three, you have reduced the total amount of biocide available to retard fouling growth on your hull. And since the biocide is released continuously and at a predetermined rate, less paint means the available biocide is depleted earlier, necessitating more frequent haulouts.