Maritime Safety Expert Was Barred From Opining on Structural Integrity
Posted on December 17, 2025 by Expert Witness Profiler
At its core, this case involves an alleged injury on a ship. Specifically, Plaintiffs Robert Mondella and Tara Mondella allege that Mr. Mondella was seriously injured when he fell from a gangway while performing services on board the JPO Capricornus (the “Capricornus”), a vessel owned by Defendants.
Defendants filed a motion to exclude the report and testimony of Plaintiffs’ expert Captain Joseph Ahlstrom.
Defendants challenge each of the enumerated opinions in Capt. Ahlstrom’s report on at least one of the following grounds: (1) that he is unqualified; that his opinions are speculative, conjectural, or otherwise rely on insufficient evidence; and (3) that he relied on principles or methods that are inappropriate or otherwise improper for expert testimony.

Maritime Safety Expert Witness
Captain Joseph F. Ahlstrom is a graduate of the State University of New York (SUNY) Maritime, with a bachelors degree in marine transportation. He completed his masters degree in transportation management with honors from SUNY Maritime College. Captain Ahlstrom has commanded six merchant ships, including a tanker, containership, breakbulk carrier, and research and training ship. He sailed for fifteen years in the U.S. and Foreign Merchant Marine. In January 1996, Captain Ahlstrom started teaching at SUNY Maritime College. During his time at SUNY Maritime he was captain of the Training Ship Empire State from 1998–2000. He also was chairman of the Marine Transportation Department from 2003 until May 2005.
Discussion by the Court
Defendants challenged each of the enumerated opinions in Capt. Ahlstrom’s report on at least one of the following grounds: (1) that he is unqualified; (2) that his opinions are speculative, conjectural, or otherwise rely on insufficient evidence; and (3) that he relied on principles or methods that are inappropriate or otherwise improper for expert testimony.
Qualifications
Defendants argued that Capt. Ahlstrom “is not a metallurgist, possesses no educational background, training, or experience in the field of metallurgy, and is not qualified to opine on metallurgical matters (i.e., whether the pin was rusted or corroded, leading it to be in a ‘defective’ condition).”
Although Capt. Ahlstrom is an expert, his expertise on “hundreds if not thousands of [gangways]” demonstrates that he has experience generally with the type of gangway pin at issue, but it does not demonstrate that his expertise extends to qualify him to render the testimony about the condition and structural integrity of the pin at issue here.
Capt. Ahlstrom does not need to be a classically trained metallurgist, but he must have experience such that the Court is persuaded that his opinions on the condition of the at-issue pin are as reliable as his opinions based on other pins that were available for him to inspect in person. Plaintiffs have failed to demonstrate that Capt. Ahlstrom has experience in evaluating the condition of gangway pins through a single photograph.
Because Plaintiffs have not demonstrated that Capt. Ahlstrom has such experience, Plaintiffs have failed to demonstrate by a preponderance of the evidence that Capt. Ahlstrom is qualified to testify about matters of deterioration or structural integrity under these circumstances.
Methodology
i. Capt. Ahlstrom’s Testimony is not Based on Sufficient Data
At bottom, Defendants relied on the fact that Capt. Ahlstrom did not inspect the relevant pin or gangway in person. Although the failure to conduct such inspection is not enough, by itself, to render expert testimony unreliable, Plaintiffs did not demonstrate that his testimony concerning his review of the available materials is reliable.
Plaintiffs conceded that without the tangible pin, their expert would not have access to sufficient facts or data necessary to determine the pin’s condition—those concessions are fatal.
If there was not enough information for Plaintiffs’ expert to determine material facts about the pin’s condition then, there is certainly not enough information now. Plaintiffs cannot credibly demonstrate that Capt. Ahlstrom’s testimony regarding the subject pin is based on sufficient facts or data. In other words, “there is simply too great an analytical gap between the data and the opinion proffered.”
That analytical gap renders the portions of the testimony that concern the condition of the pin speculative and conjectural. Because Rule 702 bars such speculative and conjectural testimony, the Court must preclude it.
ii. Capt. Ahlstrom’s Testimony is not the Product of Reliable Principles and Methods
One of Capt. Ahlstrom’s opinions is nothing more than an expert “simply accumulating and putting together one party’s story,” which is “expressly prohibited.”
Moreover, Capt. Ahlstrom’s failure to consider potential alternative explanations, and Plaintiffs’ failure to address this deficiency, further undermine the Court’s confidence that the subject testimony is the product of reliable principles and methods.
According to the Court, Capt. Ahlstrom provided legal conclusions about the duty of care and causation, disguised as his opinion.
Plaintiffs’ failure to demonstrate that their proposed expert’s testimony “is the product of reliable principles and methods,” or “a reliable application of the principles and methods to the facts of the case” is particularly troubling, as the principles-and-methods components of Rule 702 is the crux of the Court’s inquiry.
Held
The Court granted Defendants’ motion to exclude the report and testimony of Capt. Joseph Ahlstrom .
Key Takeaway
Concerns about the reliability of Capt. Ahlstrom’s reasoning and methodology, the sufficiency of available data, and the other infirmities discussed above lead the Court to the inescapable conclusion that Capt. Ahlstrom’s testimony will not assist the trier of fact. Taken together, Plaintiffs failed to demonstrate that Capt. Ahlstrom’s testimony satisfies even one of the four requirements of Rule 702. Therefore, the Court found “that there is simply too great an analytical gap between the data and the opinion proffered.” That analytical gap renders Capt. Ahlstrom’s testimony at best, irrelevant, useless, and sure to waste time.
Case Details:
| Case Caption: | Mondella V. Schiffahrtsgesellschaft Oltmann MBH & Co. KG |
| Docket Number: | 1:20cv1059 |
| Court Name: | United States District Court, New York Eastern |
| Order Date: | December 15, 2025 |





