Mildew issues on seats

[Plastik]

2014 220WSS in Seattle. Boat is stored in a rack at Skylaunch so outside 100% of the time. We use the stock tonneau bow and cockpit snap-in Sunbrella covers (with support poles in front and back) that over the years have gotten a bit ratty, a few snaps don’t work, some sags, etc. Will be buying new soon just to freshen up the boat a bit.

Question here is related to mildew growth over the winter and I think possibly related to using the Tonneau covers vs other style (like a mooring cover instead). In reading the owners manual yesterday it clearly states that the Tonneau covers are NOT intended for long-term storage as they don’t promote any airflow and may encourage mildew. My feeble belief was that because my old ratty covers don’t fit well anymore that we’re encouraging mildew.

Regardless, specific to PacNW where we get like 14 days of decent boat weather, what is the outdoor cover strategy to keep mildew at bay? I have 8 of those moisture collectors that I swap 2-3x during winter but this year was by far the worst for mildew on seats, etc.

I’m willing to look at using a mooring cover, doing the plastic wrap, removing any/all seats/cushions (even if screwed in) or other methods to not have a mess to clean in April every year. Seattle Boat graciously offers indoor storage over winter too...but it’s like $500/mth and we’d still need to pay $385/mth for our Skylaunch slot so a bit prohibitive. Do we find a different indoor solution from third party? Frankly keeping her indoors would 100% solve the issue but source and cost have been unpleasant.

Long post, yes. That said: ideas?

[Big Block Power]

Yecks sucks. No matter what I would be getting a mooring cover. Try baldmikes.Com he sells westland covers.
https://baldmikes.com/

[jma2@fuse.net]

I use a semi-custom fit cover from boatcoversdirect, which I had a marine upholstery shop further tailor the fit. It's the Sun-DURA fabric, if I recall (not the cheapest but not the most expensive option). My boat sits on a lift at the dock year-round.

At the end of the season, I take everything off the boat, including the seagrass flooring, and removable seat cushions, and then clean the upholstery with Aerospace 303 cleaner. I also make sure the boat is thoroughly dried out, and I clean the bilge and engine bay. I tried the damprid crystals one season, but found in the spring my boat essentially had buckets of water in the canisters instead of crystals; also I had some minor mildew. The last several seasons, I've used the Cafarmo Stor-Dry, which has kept the boat dry and mildew free over the winter. So if you have an electrical source, you might want to try that.

[Plastik]

Agreed on removing everything. Unf no access to power in the 4-high stacks I’m in. Will def invest in a mooring cover and try that vs Tonneau’s this winter. So then, for that matter, why use Tanneau covers at all?

[Big Block Power]

Agreed on removing everything. Unf no access to power in the 4-high stacks I’m in. Will def invest in a mooring cover and try that vs Tonneau’s this winter. So then, for that matter, why use Tanneau covers at all?

For your use I wouldn't use them at all. The bow cover is nice to put on for cool days though. But you can just close the door and do the same thing pretty much.

[ajcampen]

Agreed on removing everything. Unf no access to power in the 4-high stacks I’m in. Will def invest in a mooring cover and try that vs Tonneau’s this winter. So then, for that matter, why use Tanneau covers at all?

Save the tonneau covers for when you overnight away from home. Have a canvas shop make you a over the tower cover with vents for the rack. No water at all in my boat anymore and no mold on seats. Material is top gun. 2014 220s

[Plastik]

So I love that for a single cover. But let me clarify: in the summer we use the boat 1-2/week and every time we currently snap the bow and cockpit covers on on before they put it back up in the rack.

Is a mooring cover easier to put on and just as good, if not better than a Tonneau. From what I’m hearing, maybe so. That’s said, everyone around us uses Tonneau covers too and before coffins the dock people would happy take a $10 tip to do it for you before the boat is out away.

Is there a specific value to the Tonneau cover that I should keep using it or better to just swap to a mooring cover and use it exclusively, even for over winter storage?

[Big Block Power]

If I kept my boat outside for storage summer or winter I would use a mooring cover. On land they are easy to put on. They should keep the boat dryer. A separate bow and cockpit cover can let too much water in too easy.

[Alaskabound]

First summer I had my boat I stored it in a new garage type unit at the lake. Problem was the owner had built it so each unit was almost air tight, no air movement. So we had mildew. Moved to another new facility where that owner had open ceilings and also had installed vent fan & we never have had any problem. From November to May, I store boat in my barn, with no heat or ac but just cover it was clear plastic sheet , no mildew. So I think the more air movement you can get, the better your chances. I have a small storage room in my barn that is both heated and cooled but I still run a fan in there 24/7 all year long, just to have air movement. Maybe some type of fan in the covered boat would help. Just my 2 cents.

Dub

[Platnumtoof]

I am also in the Seattle area and experienced mold/mildew on my rear seats and engine cover. During the season my boat is on a lift and I use custom bow and cockpit covers, but in early spring and fall before my boat is put away for winter I use the full Cobalt moorage cover. The moorage cover is the original one (2012) and likely needs to be replaced as it isn't nearly as water repellant as original. I did coat it with Starbrite waterproofing spray last year, but not sure how much that helped as the mildew persists. It appears that the mildew on mine mostly occurred where the cover touched the seat, so that's something I need to figure out. I've considered a tarp around the vent holes in the mooring cover, but that's kind of an eyesore, though if it's worth it then I will give it a try. I am also going to put in a fan of some kind, though it doesn't sound like you have access to power at your skylaunch. Perhaps a solar powered one (though sun here is nonexistent for 10 months a year) would work for you.

I did notice that there was a bit more water in the boat using the bow and cockpit cover vs the mooring cover though, so that would at least help you a little bit.

I'd like to get a new mooring cover that's more waterproof, but I'm having a hard time finding a fit online for the 2012 WSS with OEM tower.

I store it in a garage for the winter, but am in the same boat as you would like to prevent this before bringing it to storage.

[Mike in SC]

Putting a mooring cover on a boat that's in the water about to be hoisted onto a rack is a bit of a pain, but probably worthwhile if it is going to stay in the weather. Also consider a deep clean followed by a treatment with Concrobium. Should help quite a bit.
It just occurred to me that a solar powered ventilator might be the answer to your problem. If you could configure it to catch sunshine and blow in one end and vent out the top...that might just work. So a search and they do come up.