Boat-Building Ergonomics
Some Accepted Measurements and Minimums
(Text excerpt from the Boatbuilder’s Notebook 2nd edition) from Glen-L Marine.
One of the fun parts of building a boat is to make changes to fit your particular needs, particularly on the cabin floor plan. In most cases unless a major weight is shifted, such changes are doable.
However, you may not have the space you think you have. A boat, unlike a house, doesn’t have that nice flat floor and the “walls” are sloping; both limiting the usable area. Thus, don’t just look at the floor plans; check the sections to find out how much usable space is available.
The best way to make changes in arrangements is to have fun making all the changes you want on the drawings. But, before seriously committing to a revised layout, wait until the hull is right side up. Only then can the full scope of the area be viewed. Now mock up your new layout, using sticks of wood, cardboard, etc. Then see if the alterations can be accomplished and figure out where you can make little compartments to stash whatever.
When making changes, questions will arise as to how big is a berth, what is comfortable seating height, etc. Obviously, you can check a chair or measure an existing item but there are a few sizes and measurements generally accepted but not cast in stone. A few of these are listed below in alphabetical order.
BERTH: 6’ 2” x 2’ 2” min.
CABINET WORKTOP HEIGHT: 33”
CABINET WORKTOP DEPTH: 24”
COMPANIONWAY: 24”+ if very short 21” (min)
DOORWAYS: 24” – 21” if seldom used.
EYE HEIGHT STANDING: 69”
EYE HEIGHT SITTING: 38”
HATCH OPENINGS: 14” x 18” min – 18” x 18” preferable
HELM (center of steering wheel to backrest): 25”
HELM (bottom of steering wheel to cushion): 11”
SEAT HEIGHT: 18”
SEAT DEPTH: 16” - 18”
SEAT SLOPE: 5 to 7 degrees fore to aft
SITTING HEADROOM: 35”
TABLE SIZE- FOUR PEOPLE: 39” x 30”
TOILET ROOM (HEAD): 27’ X 27” x 51” height (min.)
Speaking of our sister company, Glen-L Marine, here’s a salty 18-foot tug that can be built in plywood or aluminum—the Goliath.
Owner/builder Bob McKinney wrote upon launching his Goliath: Handled beautifully! Surprised that she only drew about 14” at deepest point despite 42 gallons of gas and 24 gallons fresh water in below-deck tanks. Camped onboard in beautiful little cove. The new 90-hp Tohatsu eased her along at 6 mph at about ¼ throttle. Hardly sipped gas. Installed really efficient AC/DC chest-type fridge—supposed to hold up to 84 cans beer. Must confirm! Intend week-long trip from Knoxville down past Chattanooga in couple weeks on Tennessee River. Thanks for good plans and encouragement! —Tugboat Bob •SCA•
Being over six feet tall AND having big feet, I have found the vee berths on almost all small boats to be inadequate. And now, being still tall and 76 yrs old, I find crawling into vee berths impossible necessitating a walk in type of vee berth. If designers are young and reckon their clientele to be both young and shorter than six feet........it won't work for many.
It would be interesting to know how tall Kees Prins is.