Boatyard Battles: Upgrading Lagoon Escape Hatches

How we replaced the corroded and leaking escape hatches on our 2005 Lagoon 380 S2 with new style Lagoon supplied fixed escape hatches.
by Matt, Chief Engineer of S/V Independence
Management supervision required for this project. Now get to work humans!
Like most catamarans, the Lagoon 380 is fitted with emergency escape hatches in the aft cabins. These are hatches you hope you never have to use: if the boat capsizes, you can get out and walk onto the underside of the bridge deck where you can tie off a life raft and cuddle your EPIRB to make sure it’s feeling loved after years of neglect. Fountaine Pajots and some St Francis’ catamarans have the nicest hatches of all, they are usually up slightly higher. Smug owners of these boats like to leave them open for a nice breeze, which I bet is amazing. Lagoon owners know that this isn’t in their future: Lagoon mounted these hatches a mere 2-3 inches above the waterline. They are constantly splashed while sailing. At anchor, one good wake and the aft cabin is flooded. Nope, those things stay shut unless called upon. 
Original hatches installed on our boatyard neighbor (a 410 S2). Theirs is in pretty good shape!
But here’s the real rub: the older Lagoon boats used a modified Lewmar deck hatch. It’s identical to the hatches above (which were never meant to be so close to the waterline; which leak during most light drizzles; etc) except the escape hatches have a beefier bottom frame, better hinges, hefty exterior handles, a second rubber seal and a second set of securing handles. I bet this solution worked marvelously until the boat’s warranty period expired. Then, the sea takes it’s toll and the hatches begin to corrode. The aluminum frames simply fall apart from the inside out. Lagoon knew it had a problem and new boats have a custom designed fixed safety-glass deadlight (with a big hammer to break it open should you need to). Lewmar and Lagoon stopped selling parts for the old escape hatches long ago. You can, however, buy parts for the standard deck hatch that it is based off of--the Lewmar Medium Profile Size 44.

Meet-ups with other owners have revealed the number one solution to dealing with these deteriorating hatches: don’t touch them! Don’t ever open it. Some people seal the hatch in with silicone to stop leaks. Others nurse their hatches along with whatever new parts they can scrounge up (like we did just one year ago). If your hatches are in decent shape, this is okay. In our case, the hinges had corroded to the point where the hatch is basically held on by the handles. 

A Google search will reveal a lot of pissed off people on the internet about this whole situation. "Lagoon should stand behind their products,” they cry from their soapboxes. “They should provide a fix.” “Unacceptable, ridiculous, preposterous!” 
All true. So if Lagoon did provide a solution, what would it be? I bet it would be a whole new hatch. I bet it would be whatever hatch they put in the new boats now! They are still making 380s after all!

So I asked around, and I didn’t get any real answers. A member of the Facebook Lagoon Owners forums mentioned he had replaced one of his hatches with a new fixed hatch on his 440. Hum! By emailing the Beneteau Spare Parts folks in South Carolina I was able to get a price and size on the new hatches, but little else. The cutout is the exact same size, the exterior diameter is the exact same size--so I decided to go for it. And so we planned a haul out, got our new hatches and monogrammed Lagoon glass breaking hammers, and set out on another adventure in boat repair! Yay! This project took us about 4 partial days, leaving time for fiberglass and gelcoat to cure.


24 - pack favorite beer, wherever, price varies (your mileage my vary)
2 - fixed escape hatches, “071068 Fix Hatch 528x528 Survie Glass”, Beneteau Spare Parts, $855/ea
2 - glass breaking hammers,“072152 Marteau Brise Vitre”, Beneteau Spare Parts,  $89.85/ea.
(Note: the freight charge from France was $35 and the order took about 2 weeks to arrive. If you order on their website you get 15% off, which brought the grand total to $1641.06)
24 - M5x0.8 nuts (stainless), wherever, about $9
24 - M5 (or close equivalent) fender washers (stainless), wherever, about $9
1 - Debond Marine Formula spray, West Marine, $35
(Note: This stuff really works! It says so on the bottle. For loosening up old 5200 and adhesives.)
1 - 10 oz. 3M 5200 white, $20
1 - roll Butyl tape
Misc - angle grinder, pry bars, screwdrivers, another case of beer, fiberglass and gelcoat supplies (maybe), drill and bit, cardboard boxes, wine, management supervision, 8mm socket and wrench, something to mount the hammer to the wall

Below is what I did and how I did it. It might not be the right way or the easy way, but the job got done.

Step 1: Out with the Old
The first step was the worst. -Marvin

Ponder if you really want to do this while you enjoy a cool beverage. 

The first thing to do is get all of the wood bits away from the hatch in the cabins. Not as easy as it sounds. I doubt any two Lagoons are alike when it comes to cabinetry, because no two matching pieces in my boat match. In the end I discovered that the wood panel around the hatch is glued onto the hull only near the hatch (meaning with a sharpened scraper, or thin chisle and hammer, you can break it apart. Spraying the Debond in the gap also helps. There are also long, self tapping screws holding it in place from behind the wall panel, aft side at the top. Didn’t know that until it was too late 😔Some sides of the panel were glued to the adjacent cabinets, which was easy enough to undo with the scraper. The small wood panel below is screwed in from each side with two large screws. I couldn’t get to some of these to undo them. As long as the top of the wood is left in good shape and it’s not broken, you’ll be in good shape. With the wood out of the way, you can see a large bead of 5200-ish stuff along the gap between frame and hull. Using the Debond and a scraper, remove as much as you can. You're going to need another beer.

Now on the outside, remove the old hatch from the frame. This was easy for us because we did it last year, you might have to grind off the hinges. Once the hatch is off, the frame is attached with 12 self tapping screws and copious amounts of a 5200-like product. You will have to wedge a pry bar under the frame, spray in Debond, use the scraper to break the goo apart, then pry up a little more. Get yourself another beer; it's a painful process. I found that using the angle grinder to cut through the four corners of the frame allowed me to remove it in sections. Either way, I found it was impossible to not damage the gelcoat and fiberglass. Damage was minimized by using lots of the Debond, letting it sit, and being as gentle as possible. You definitely don’t want to just forcefully yank the thing off, it will just take a large part of the boat with it. If that happens, you'll need to set aside the beer and upgrade to straight rum.
Out with the old! Notice I cut the frame to help get it off and minimize damage to the fiberglass underneath.
Step 2: Clean Up What You Broke, Doofus!
The second step was the worst too. - Marvin

So now it’s off, but there are chunks of fiberglass missing and it looks like a disaster. Who’s the knucklehead who told you to do this anyway? Have a beer. Luckily, I’m pretty handy with fiberglass repairs and since it’s on the bottom of the boat, it’s the perfect opportunity to work on my gelcoat skills.

I sanded and feathered out the damage and removed any bits that got crushed or delaminated. I measured using a caliper on the good bits and planned to build up the bad to the same final width. The hull around the hatch was variable, anywhere from 4 to 10 mm from the factory. Using West Systems epoxy and 0.75 oz. biaxial cloth, I made patches. I also added glass to the back side of the hull to stiffen the top of the cutout, which were very thin (4 mm) from the factory. In the end, I got the entire cutout to be between 6 and 10 mm. Celebratory beer time!

After the epoxy cured, I repaired the gelcoat with a standard, off the shelf white. I applied with a Preval sprayer, and the results were pretty good if I do say so myself. 
All cleaned up with new glass and gelcoat.
Step 3: Install the New Hatch
The third step I didn’t enjoy at all. After that, I went into a bit of a decline… -paraphrasing, of course, Marvin the manically depressed robot. 

The new hatches are very heavy and very thick. They are made with an anodized aluminum (I think) frame. The underside has 12 5-mm stainless, threaded rods installed for through-bolting. Using a large piece of a cardboard box, I made a drilling template for the holes. I didn’t have much luck and wound up oversizing the holes slightly to get it to work. In the process, I bent one of the bolts. Don’t do that. Did I mention the hatches are in the neighborhood of 30 lbs. each and you’re holding it basically over your head? Better rest with a beer or two.
Fresh from France. 
Once you know it will fit, time to install! I used butyl tape in a solid strip on the hatch around all the of threaded rods. Then I added an inner and outer bead of 5200. You might want to be smarter than I and put masking tape around the frame of the hatch to make a clean bead. "Pity the fool” who has to remove this one! With one person outside holding the hatch in place, a hapless helper (who is just here for the beer) goes inside and installs 4 of the fender washers and M5 nuts. Once in place and secure, you can go inside, add another bead of 5200 between the hull and lip of the hatch, then 5200 the screw holes prior to installing the rest of the washers and nuts. Remember to remove and add 5200 to the original four that held it on. Tighten the nuts gradually and opposite each other like tightening a cylinder head. From the outside, double check that the hatch is sitting flush on the hull and clean up any mess the 5200 made. I really hate that stuff. Maybe beer will get it off your hands? Taken internally of course...
Completed underside of hatch (pre replacing the wood interior). Probably needs more 5200.
Now that it’s in, simply reinstall the wood. The veneer strip along the cutout was damaged on mine from the leaky hatch, so I replaced it. Look for a future post about fixing up Beneteau/Lagoon veneers because it’s a skill I’m working on.

The final bit is installing the hammer. It needs to be right next to the hatch and be very secure. Remember, when you need it you will be upside down! We sewed up a snapping leather-like vinyl mount for it which looks pretty sharp. I was unable to find the plastic box that Lagoon uses on the spare parts site, and I never asked. 

So there you have it. It’s not easy or fun, but the new hatches are a direct replacement for the old. No modifications are necessary…just remove the old and put in the new (just remember to add in standard boat aggravations, difficulties and hangovers!)

Completed installation ready for splashing.
How many beers does it take you to get through a boat project? 

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  1. I see you listed the most important project supply first :-)

    1. We can live for 4 months in the Bahamas on one case of beer, but 2 weeks in the boatyard? We're going to need a supply run!

  2. I've got three things to say: First, great job! Second, $855 per hatch? Ouch! And third, is Hastings always that cute or do you prep him for photo shoots?

    1. Yes, it's been a very expensive and somewhat demoralizing summer. Hastings is always this cute. It's painful!

  3. Great description, Matt. You did what I never got around to doing: write up the process of replacing (or in our case, fixing) the emergency hatches. It was an article idea I had once upon a long time.

    What we did get around to was fixing them multiple times, in the form of taking them out, removing all the old caulk, cleaning them thoroughly and re-bedding the whole thing(s).

    We had an older Fountain Pajot and our hatches were in about the same spot as on your boat, a mere inch or two above water level - flat water level. After a period of time (and in the beginning of our ownership), they leaked. And, again. We fixed them in boat yards a few times and twice (or should I say three times) while anchored in a VERY calm anchorage (in Grenada and Panama), constantly fearing anyone would pass by in a dinghy. Stressful! Three times, because the second time doing this, we managed to get salt water in between the window and the caulk upon completion of the project, didn't trust it, had to get to a marine store again, hours away, and repeated the whole 6-hour project immediately, at night this time!!! The trick: a deflated dinghy, so one of us was on the "outside" (me) and the other inside the cat (Mark). We did become professionals after a while and the last three years of cruising, we were leak-free. In that area anyway. :-)

    PS: I totally agree with you: do not open the emergency hatches unless needed for their intentional use. It is asking for trouble (and worrisome to get leaks quicker).

    1. Man, I really hope our second time works.....this whole in the water at night sounds like a prelude to selling the boat and never looking back! There are upsides to cats, but we are really in the downside part when working in the yard, everything has to be done twice and gets pricey quick.

  4. Yep. But, think about all the comfort when you are back at anchor. :-) The negatives: saildrives and emergency hatches. The positives, other than the obvious ones: you have a "spare" engine (when one dies) and an "example" engine to compare to when working on the other one.

  5. How many beers you ask? I need a couple just to recover from reading your post!


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