Model Expo Waterline Marker Tool for Hobby Model Ships - Model Shipways A quick and easy way to get a straight line on your hull for painting, coppering or planking. Basswood construction with lock tight wing nut. Adjustable from 1-1 /2 to 9-1/4. Base 3x5 height 11. Model Expo has been serving hobby enthusiasts with precision Models since 1976, and is a hobby tools manufacturer, distributor, and reseller.