We describe a compact flow-type shipborne fluorimeter, which is intended for measurements of spectral components of laser-induced fluorescence of seawater and allows one to make on-line determination of the chlorophyll "A" concentration as well as estimation of the level of the dissolved organic matter fluorescence. The fluorimeter is a monoblock of 20 × 20 × 60 cm in size comprising a flow-type optical cell, a fluorescence detection system, a laser (Nd:YaG, 532 nm), and a computer. The fluorimeter can be employed from onboard any nonspecialized vessels.