Many people will have this question in their mind, “How long can you leave a boat in the water?” Let’s find out that, and it may vary a bit and mostly depends on the water where you keep the boat in.
You can leave the boat in the water for a week without worrying about the growth of algae or anything on the boat hull. Still, it depends on the water where you keep the boat in, but mostly one week after, you’ll start seeing growth on the boat hull.
The essential thing about the growth is it depends on the type of water where you keep or store the boat in. Some waters results the growth in less than a week, and some other waters will results the growth in 2 weeks.
Generally, if you store a boat in the water for a week or less, nothing will happen to the boat, and most probably, there won’t be any growth. And generally, after 4 or 5 days, it gets a slimy feeling, but it’s still easily scrubbed off (go to the bottom for the growth prevention tips).
If you aren’t going for bottom paint the boat, you need to commit to constantly wiping down the hull at least once a week. If you have bottom paint, then you can leave the boat for 3 or 4 weeks without any inspection or so. Otherwise, you need to inspect and clean the hull at least once a week.
If you are storing the boat for a long time, maybe 3 or 4 weeks, you need to give some protection for the boat hull, such as bottom painting. Otherwise, if you store the boat at the marina, then you can pay for the diver to clean the boat once a week or so.
If you are an environment lover, then the best option is to keep a diver to clean the boat hull once a week. Generally, some marinas will have divers that clean the boat hull regularly if you leave the boat for a while in the water, but it all comes at a price, and it depends on the place where you live.
How long can you leave a boat in the water without bottom paint?
You can leave the boat in the water without bottom paint for 3 or 4 days without worrying about the growth of algae or anything on the boat hull. Bottom paint will prevent the growth of algae or barnacles on the boat hull for a long time than without bottom paint.
However, it is impossible to stop the growth on the boat’s hull, but you can prolong it by applying an appropriate anti-fouling paint on the boat hull.
Sometimes, it can form growth along the hull’s waterline even if you leave it for 2 or 3 days. So, it all depends on the type of water where you will keep the boat in.
If you aren’t interested in applying the bottom paint, then you need to clean the boat regularly for every 4 or 5 days, or at least once a week, by taking the boat out of the water or by paying others (diver) for cleaning the hull.
Cleaning the boat hull regularly at least once a week if you leave or store the boat in the water is the only solution to prevent the growth on the boat hull if you don’t have bottom paint on it.
Bear in mind that keeping your boat in the water without a barrier coat is a crapshoot. Some people have no problem; others do. There are some spray waxes and sealants that will last 3 weeks or so; you can use them as well if you don’t want bottom paint.
Check my article on Why do boats need bottom paint? (opens in a new tab) to know more about the bottom paint uses and who are required to have it on their boats.
How long can you leave a boat in freshwater?
You can leave the boat in the freshwater for a week without worrying about the growth of algae or anything on the boat hull. The algae can start growing within 3 or 4 days, but you can easily remove them by using 3 m pad or pressuring washing the boat.
Freshwater or saltwater are not the causes for the growth of algae or barnacles on the boat. It depends on the organisms that live in the water. For example, Barnacles are exclusively marine and tend to live in shallow and tidal waters, typically in erosive settings (source).
Like that, it depends on the organisms living inside the water where you keep the boat in.
How long can you leave the boat in saltwater?
You can leave the boat in the salt water for a week without worrying about the growth of algae or anything on the boat hull. The other problem with salt water is corrosion (rust), so it is better to remove the boat regularly every week to prevent growth and corrosion as well.
As I said, saltwater or freshwater are not the causes for the growth of algae or barnacles on the boat. It depends on the organisms that live in the water. Saltwater causes many problems such as corrosion, bottom paint problems, etc. not only the algae or barnacles.
That is the reason why people will not show interest in storing the boat in the saltwater. Check my article on the Effects of saltwater on boats (opens in a new tab) to know all the effects of saltwater on a boat in detail and prevention tips as well.
How to prevent the growth on the boat hull?
There are generally two types of growth; soft growth (which are easily scrubbable) and hard growth (which are not easily scrubbable). Algae on the boat hull can be easily scrubbable, but barnacles are not easily scrubbable, and it requires a paint scrubber or any tool to remove them.
However, it impossible to prevent the growth on the boat hull, but by applying bottom paint on the boat hull, it will prolong the process. Mostly for all the types of growths (algae, barnacles, organisms, etc.), applying the bottom paint and cleaning the boat hull regularly is the only solution to prolong the growth.
Before seeing how to prevent and clean the boat hull for each type of growth separately, we will now see a product that removes mainly the algae and tough stains out of the boat hull without even scrubbing them with a brush hardly. That is Star Brite hull cleaner (linked to Amazon) or click on the image below (linked to Amazon).
The main advantage of the product is after applying it to the boat hull; there is no need to scrub the boat hull roughly, or hardly, just pressure washing the hull after some time is enough.
You can spray this on the boat hull with a garden hose and leave it for a while after spraying it on the boat; then pressure wash the boat hull. Still, if you found any algae on the hull, you can remove them quickly (easily) with a 3 m pad.
But if you have an aluminum boat, then use Star Brite Aluminum cleaner (linked to Amazon), which works very well for aluminum boats. It removes the spots on the boat hull as well. Apply that on the hull and leave it for some time; enough.
And while using these Starbrite products or any other etching acids on the hull, make sure that you don’t use it on galvanized steel bodies because zinc on the surface of the trailer or anywhere you have will react with the acid, which causes problems (for Starbrite it is sulphuric acid).
How to prevent algae on a boat hull?
The algae growth on the boat hull can be stopped or prevented by using anti-fouling paint because anti-fouling paint has biocides in it (copper), which will start leaching out over time and stop the prevention of growth of algae on the boat hull.
Bottom paint is sufficient to prevent the algae growth on the boat hull. And you should change the bottom paint yearly if you go boating regularly. Bottom paint leaches out over time, preventing the growth of algae on the boat hull.
How to clean algae on the boat hull?
You can clean the algae on the boat hull either by pressure washing the hull and scrubbing the hull or by using any products such as hull cleaner to do it more quickly. Using these products will give the best results than just pressure washing the hull if you have any hard stains or so.
It is up to you; however, you want you can wash the hull, but if you have hard or tough algae stains on the hull, then use any hull cleaner such as Starbrite hull cleaner (linked to Amazon) or any other products to remove them quickly, which will do the work quickly and adequately.
How to prevent barnacles on a boat hull?
Barnacles on a boat hull can be stopped or prevented to some extent by applying bottom paint on the boat hull. Cleaning the boat hull regularly will prevent the growth of barnacles on the boat hull.
Barnacles are exclusively marine and tend to live in shallow and tidal waters, typically in erosive settings. That doesn’t mean that barnacles won’t grow in other waters.
How to clean barnacles on the boat hull?
You can clean the barnacles on the boat hull by using a pressure washer, or you can do it manually by using a paint scrubber. But while scrubbing with the scrubber, it can peel out the bottom paint as well, so you need to it with care while removing barnacles manually with a paint scrubber.
Pressure washing the boat at normal speed (4500 rpm) will give the best results. It is up to you; however, you want you can wash the hull, but after removing the barnacles if there are any barnacle stains on the hull, then use hull cleaners such as Starbrite for normal boat hulls and Starbrite for aluminum boat hulls (linked to Amazon) to remove them.
But cleaning the boat hull manually with a paint scrubber can peel out the bottom paint as well (if you have bottom paint), which can result in exposing the gel coat to the water, which eventually results in causing blistering and algae growth as well since the bottom paint is not there.
To prevent peeling off the bottom paint while scrubbing the boat hull, either you need to do it carefully, or you can use hard bottom paint, such as applying the anti-fouling paint with a mixture of epoxy resin and a high percentile (99.99) of copper powder with it.
That is tough paint, and even if you scrub the hull with the scrubber, the paint will not be peeled out easily or quickly. So, it is better to use hard paint once, instead of applying the bottom paint, again and again, every time after scrubbing the boat hull.
How to prevent blisters on a boat hull?
Blisters on a boat hull can be prevented by using a hard bottom paint (for example, applying the anti-fouling paint with a mixture of epoxy resin and a high percentile (99.99) of copper powder with it) on the boat. By doing that, water will not reach the gel coat layer on the boat hull, preventing blisters.
Blisters won’t be seen on the boats often if you have good bottom paint on the boat. Blisters occur when the boat sits in the water for a longer time, which results in the gel coat absorbing the water and forming bubbles kind of things on the hull surface, and the best solution for that is a coat of epoxy.
If you keep the boat in the water for a long time without bottom paint, you will increase the chances of getting blisters on the boat hull. But if you had hard bottom paint on the boat hull, then it will give some protection.
And still, it is hard to tell, some people will get blisters on their boats quickly and for some people, it won’t form at all. So, better be prepared for it and apply bottom paint to prevent or prolong the process if you keep or store the boat in the water for a long time.
How to clean blisters on the boat hull?
You can clean the blister on the boat hull by break opening the blisters and then scrubbing them properly, removing all the broken particles and finally applying the paint on the blister patches. After finishing that, apply epoxy resin on the boat hull to prevent any blisters in the future.
After painting the boat hull, apply hard bottom paint (for example, applying the anti-fouling paint with a mixture of epoxy resin and a high percentile (99.99) of copper powder with it) on the boat hull. By doing that, water will not reach the gel coat again.
By having a hard bottom paint on the boat hull, you no need to worry about peeling off the bottom paint while scrubbing with a paint scrubber, and you need not worry much about any growth as well even if you store the boat for 2 or 3 weeks straight in the water.
Check BoatUS website for info about the prevention and cleaning of blisters on the boat hull click here (opens in a new tab).
Bottom line
Bottom paint on the boat hull will prevent or stop the growth of algae or barnacles or anything on the boat hull for some time, not entirely. If you have bottom paint on the boat hull, then you can leave the boat in the water for 2 or 3 weeks straight in the water without worrying much about the growth.
Still, with the bottom paint on the boat hull, you will see a little bit growth on the boat hull even if you leave it for 2 weeks or 3 weeks, but that growth is not tremendous (meaning, it’ll be easy to remove) or it is very slimy. It can be easily removed with a 3 m pad or by using a pressure washer.
And the same thing will not be with a boat hull without bottom paint. If you leave the boat without a bottom paint in the water for a water straight 2 or 3 weeks, there will be tremendous growth on the boat hull, and it’ll not be easy to remove that growth.
So, it is good to bottom paint the boat if you keep or store the boat in the water for a long time (maybe 3 or 4 weeks or months). Or if your marina provides divers, then pay them so that they will clean the boat hull once a week or so.
Bear in mind that keeping your boat in the water without a barrier coat is a crapshoot. Some people have no problem; others do. There are some spray waxes and sealants that will last 3 weeks or so; you can use them as well if you don’t want bottom paint.