Santos-Rodriguez v. SeaStar Solutions, 858 F.3d 695

On June 25, 2010, Bernardino Santos‑Rodríguez was ejected and severely injured when a ball‑joint rod end in a 2002 Seastar hydraulic steering system fractured due to corrosion. The boat owner (Viera) had purchased the boat used.
The Seastar steering system manual advised bi‑annual inspections by a qualified mechanic and general checks for leaks/damage but contained no specific warning about rod‑end corrosion.
Viera did not read the manual or keep maintenance records; third‑party mechanics performed maintenance but did not report the corroded rod end to Viera.
Santos and four relatives sued Seastar claiming design defect and failure‑to‑warn; district court granted summary judgment to Seastar and dismissed derivative claims by relatives; plaintiffs appealed.
The district court excluded expert deposition testimony that Seastar used a less‑suitable stainless steel because that theory was not in the expert’s written report; the expert report focused on warnings, not a design flaw.
The First Circuit affirmed: it held plaintiffs failed to raise triable issues on both failure‑to‑warn (no causation because warnings were not read) and design‑defect (no evidence tying corrosion to a defective design). Derivative claims failed as a result.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Failure to warn — causation	Manual lacked corrosion warnings; expert tied corrosion to failure, so omission could have prevented injury	Owner/mechanics did not read or rely on the Manual or labels, so any omitted warning could not have caused the injury	No causation — summary judgment affirmed
Design defect — existence of defect	Rod end failed in service; malfunction and expert linking corrosion to failure suffice to show defect	No evidence product design made rod especially susceptible to corrosion; expert report did not identify a specific design defect	No triable issue — summary judgment affirmed
Admissibility of expert testimony	Deposition testimony that stainless steel choice was poor supports design defect theory	Deposition advanced a new theory not in the expert report and was properly excluded	Exclusion upheld for purposes of summary judgment; plaintiffs relied only on report
Derivative claims by relatives	Relatives assert damages derivative of Santos’s claims	Relatives’ claims depend on success of Santos’s claims	Derivative claims fail because underlying claims fail

Cruz‑Vargas v. R.J. Reynolds Tobacco Co., 348 F.3d 271 (1st Cir.) (elements for failure‑to‑warn under Puerto Rico law)
Rodríguez‑Méndez v. Laser Eye Surgery Mgmt. of P.R., 195 D.P.R. 769 (P.R. 2016) (insufficient to show defect merely because product produced an abnormal result)
Pérez‑Trujillo v. Volvo Car Corp., 137 F.3d 50 (1st Cir.) (malfunction can be circumstantial evidence of defect in manufacturing‑defect context)
Bingham v. Supervalu, Inc., 806 F.3d 5 (1st Cir.) (standard of review for summary judgment)
González Figueroa v. J.C. Penney P.R., Inc., 568 F.3d 313 (1st Cir.) (derivative nature of relatives’ tort claims)