Watertight Companionway

Traditional sliding companionway designs seem to be the standard, few other options are available. However, we were not satisfied with Dawn Treader’s original design. While researching watertight designs and oceangoing rowboats, we found interesting hatch options that looked to be compatible. We chose the Lewmar Ocean 70 hatch for its large entryway, strength, and watertightness.

A few things changed simultaneously with the new companionway; look for new posts coming soon! Our cockpit footwell volume was reduced. Cabin ventilation was enhanced with the addition of a Lewmar Ocean 30 below the nesting dinghy. Inside the cabin, we now have more space! Our galley area has more elbow room, the new navigation station is in progress, and the cabin design is more open. The cabin sole also has 2 more usable feet of space (we are installing new sole as a result of the water tank project), and now there is ample room for a yoga mat!

We are happy with the companionway redesign! Exit and entry are easier than before, and we are excited to test our watertight hatch at sea! With this big project done, we are one large step closer to sailing.

18 thoughts on “Watertight Companionway”

      1. A what angle did you construct the hatch or what is the measurement from your cabin aft to the outside of your new companion way ?
        My outboard well is complete and I would like to start with the rough cutting and supports for “your” companion way hatch , thanks Harald


      2. I would like to see how your project goes if you have time to send some pictures. The angle of the hatch is close to 45 deg but slightly more vertical. 45 degrees gives good head clearance below, reasonable bridge deck height outside, and allows for some forward motion of the body as one descends into the cabin. Which hatch are you thinking of using?



      3. hi Brian and thanks for the reply , the hatch I got is used from the marine consignment store and measures 27″ outside square and 24″ clear inside
        My boat is a little smaller than yours as you know and 45 degree will take quite a bit of cockpit length . However I will still proceed with a slightly steeper angle .
        I would like to send you pictures and my iPod will not let me copy and paste for some reasons
        I will find a way !! Harald


  1. What a great idea. Another Safety feature if you were in really bad weather and at risk of rolling. It would certainly keep the water out. It does have a rather large step over though so I’m interested to know how it goes entering/leaving and whether it has been a trip hazard at all? Thanks


    1. Thanks for the comment and question Noel. Getting in and out of the companionway is easy and secure. The height of it matches the previous bridge deck which had to be stepped over in the original design. When we have time we plan to make a video demonstrating entry/exit/use of the hatch.


    2. I also see you asked about through hulls. We fiberglassed over through hulls for the head, sink, engine, depth transducer, and speed log. We replaced them with systems not requiring through hulls: sawdust head, bucket sink, outboard engine, lead line for depth, and gps for speed. Two through hulls remain, both for the cockpit footwell drains. These are individually isolated from the rest of the boat in watertight compartments, minimizing risk in the event of a valve or hose failure.


  2. I have a few practical questions about this modification.
    1. How do you open/close the hatch from the outside? Is it possible to lock the hatch when you’re away from the boat?
    2. Are you worried about being trapped inside if the boat capsized while you are inside with the hatch sealed? Or maybe this is a feature and not a bug since the boat would ideally right itself quickly if it doesn’t take on too much water?
    Looks like a great design. Thanks!


    1. Hi David, good questions. The hatch is a type that is designed to be opened from the inside and outside. The hatch locks easily from the inside as designed. To lock it from the outside when we leave the boat, we fit a heavy duty eye strap to the aluminum that we pad lock to another eye strap fitted to the boat. We aren’t concerned about being trapped inside during a capsize because of the limited time spent inverted being a ballasted monohull. We are more concerned about reducing flooding during a capsize which the watertight hatch should do.


  3. Absolutely love this design. My wife and I hate the companionway drop boards. Have been planning a traditional door with a portlight in it for light, etc. but adding another Lewmar hatch like yours on the companionway is very appealing.

    Beautiful work guys, having had it installed now for some time do you still like it and what if any are any drawbacks you have experienced.?

    SV Endurance


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