Waterline Systems


Frequently Asked Questions


Q1. Why does my boat need fairing?

For a more detailed answer to this important question, see the page called “Why Fair?” in the “Services” section of this website. The short answer is that resins shrink when they cure, and they don’t shrink uniformly. This leads to random bumps and hollows on a hull right out of the mold. Some boats have more unevenness than others, but ALL of them must be faired to bring them to the designer’s intended ideal hull shape.

Q2. Isn't smoothness an indication of fairing?

Fairness and smoothness are two different things. Fairing means evening out a hull’s bumps and hollows, whereas smoothing means making the surface feel slick and polished. Of these two factors, fairness is by far more important when it comes to maximizing speed. If you need more convincing, read our “Why Fair?” page.

Q3. Why not the take the cheapest bid for bottom fairing?

The answer to this one is you get what you pay for. Properly fairing a hull takes time, so if you get a very low bid it probably means that the job won’t be done as it should be. At Waterline Systems, we are highly skilled, experienced, and efficient at fairing hulls. Our prices are fair for excellent work.

Q4. Can I fair my own keel and rudder?

Not if you want great results. Keel and rudder fairing is much more complex than bottom fairing because there is more to getting the shape exactly right than just sanding highs and filling lows. And with keels and rudders, very small mistakes in shape can create significant detriments on the racecourse. That’s why this work is best left to experts.

Q5. Club Racer vs. Grand Prix – What’s the difference?

In a word, the difference between these two basic levels of fairing is time. Block sanding is the most time-consuming part of any fairing job. With every block-sanding pass, the surface gets a bit fairer. In a Grand Prix job, we devote some additional time to the block-sanding process, and we also do some extra work filling hollows with epoxies. So though the Club Racer bottom is fantastic, but the Grand Prix bottom is even better!

Q6. What is the Maintenance / Scuff and Shoot bottom?

Over time, bottom paint loses its effectiveness and epoxy primer gets a bit tired. Boats with a Waterline Systems bottom tend to get wet sanded a lot, so eventually the paint gets thin. The Scuff and Shoot is a refresher. Since we already know what’s on the bottom of our customers’ boats, we can block sand the existing paint, reshoot, and then wet sand. Because the Scuff and Shoot gives an extra fairing pass, the bottom comes out better than ever!

Q7. What is the Cruising / Daysailer Bottom?

There are plenty of people who don’t race their boat but who still want a higher quality bottom paint job than they can typically get at their local boatyard. These are the customers that the Cruising / Daysailer bottom is designed for. We sand, apply Interprotect 2000, sand and prep that coating, and then spray on the customer’s choice of antifouling. The bottom will get a bit fairer, but we aren’t spending our time and the customer’s money fairing out all the bumps and hollows. What the client does get is a nice sprayed application of bottom paint, which is a whole lot smoother than a roller job!

Q8. What’s up with the hard line where the bottom job ends?

There is a definite line, almost a ridge, where a Waterline Systems bottom job ends. We position this line several inches above the static waterline. This line can bother some people, but it shouldn’t. Even when immersed, this line is in the very top layer of the water, which is an area that is very turbulent and mostly bubbles. The smart guys tell us that having this hard line makes zero difference to boat speed and may actually create lift going upwind, like a chine does. Hmm. Maybe that does make sense. Anyway, the line in no way impairs speed. It’s a natural outcome of the bottom-fairing process.

Q9. What products do you use?

Below the waterline we exclusively use the AkzoNobel line of Interlux products. This includes solvents, epoxy fillers, barrier coat, primer, and antifouling coatings. Modern coating systems are all designed to work together chemically. And since the people who develop these products have PhDs in chemistry, we do what they say works! Interlux also stands behind our applications. Above the waterline we use Awlgrip, which is another AkzoNobel product. After some 25 years, Awlgrip has really earned our trust. It can be difficult to work with, but we have the necessary experience. Simply put, Awlgip gives the best finish possible, and it’s the most durable topside product on the market.

Q10. Couldn’t you use less expensive products?

Yes, the materials we use are expensive, and clients occasionally ask us if we could use less expensive ones. There are two good reasons why we don’t. First, materials are a small percentage of the overall cost of a project. The vast majority of the cost is for labor. Switching to cheaper materials isn’t a cost-cutter. Second, the materials we use are the ones that work best. We stand behind every job we do and our suppliers stand behind their products. In the end, our customers win.

Q11. What are my options for bottom paints?

For dry-sailed boats we use VC Performance Epoxy, which is a white epoxy paint that cures extremely hard. For the purposes of wet sanding to a great finish, harder is always better. For wet-sailed boats we use an antifouling paint. Baltoplate is our default choice for boats that race in salt water. It cures the hardest of the paints we’ve tried and gives the best wet-sanded finish. Additionally, VC Offshore is also very hard and comes in more color choices. For boats wet sailed in fresh water we like VC-17. We think it has the most effective antifouling properties, but the thinness of the coating makes it a single-season paint.

Q12. What if I want a white racing bottom on my wet-sailed boat?

If you really insist on a white antifouling racing finish, Interlux’s Trilux is what we recommend.

Q13. What about ablative paints?

Waterline Systems doesn’t recommend any ablative paints for a racing finish. These paints produce their antifouling characteristics by being really soft and slowly ablating off during the course of a season. Because they’re soft, they don’t sand well. They also need a thick application, which is another reason why they don’t produce a good racing finish. For a cruising or day-sailing finish, they are just fine.

Q14. How do I maintain my Waterline Systems finish?

For a dry-sailed boat with VC Performance Epoxy on the bottom, you need to keep it clean. Every time you haul out, you should rinse the bottom with fresh water and wipe it down with a soft sponge or cloth. Use dish soap in your cleaning water as needed. Never use a scrubber pad or an abrasive cleaner. If there are bits of tar on the bottom after a long road trip, a bug and tar remover purchased at an auto parts store can safely remove blemishes. In addition to the rule of never using anything abrasive on the bottom, also avoid applying waxes and polishes. These products don’t offer any speed advantage, and they can impair our ability to refresh your bottom finish at a later date with a Scuff and Shoot.

For a wet-sailed boat, an antifouling paint alone is not enough to keep algae from accumulating on the bottom. This growth must be removed manually on a regular basis. For this job, make sure that you or any divers you hire never use an abrasive scrubber pad on the bottom. Clean the bottom frequently with a soft rag or sponge – nothing more abrasive than the 600 grit that was used to polish it.

Q15. What about seasonal bottom maintenance for wet-sailed boats?

The hard antifouling paints we use need to be immersed in water to retain their effectiveness. When they’re exposed to air, the very top layer of paint oxidizes and “locks in” the biocides. This means that you should wet sand your boat bottom right before spring launching in order to remove the oxidized layer and expose fresh paint.

Q16. What’s the proper way to wet sand my boat’s bottom?

Dunk a squeegee into a large bucket of absolutely clean water with a good squirt of dish soap in it. Use the sponge side of the squeegee to wet down the hull with full fore and aft strokes. Then, using an 8-inch rubber sanding block, wet sand the surface so as to remove just a tiny, uniform layer of paint. You can use the blade side of the squeegee to wipe the water and floating dust away, enabling you to see where you still need to work. Be sure to change your sandpaper often. Also, keep your sanding block an inch or two away from any edges, which later should be delicately hand-sanded. For a more detailed discussion of wet sanding, see the ”Maintenance” page in our “Services” section.