Primer and Punishment

Primer and Punishment marks the fifth in the delightful cozy mystery series from Diane Kelly set in Nashville, Tennessee. Whitney Whitaker has a knack for nailing down murderers . . . but this time she might just come unmoored.
Carpenter Whitney Whitaker and her cousin Buck are looking once again to rehab and resell a house, only this particular house is made of fiberglass, floats, and has been dubbed the Skinny Dipper. The old houseboat sure could use some work, but the unusual project has Whitney bubbling with excitement.
The charming and handsome Grant Hardisty lives on the cabin cruiser in the adjacent slip, but the cousins soon learn he's left a half dozen angry ex-wives in his wake and made enemies of all sorts of unsavory folks. The man is clearly caught in an increasingly dangerous current with no life preserver in sight.
Whitney and Buck are spraying primer on their houseboat when—KABOOM!—Grant's boat blows sky high with the man himself inside. Detective Collin Flynn has no shortage of suspects, but the waters become muddied when several of them confess to the crime. Is one of those who confessed truly guilty, or are they taking a dive for someone else? When anonymous threats are made against the cousins, Whitney must quickly determine who killed their neighbor at the lake, or she and Buck might also be sunk.