Profile
“Success is when we resolve a client’s issue, and they feel supported and genuinely happy with the outcome”
George Louca,
3LANE Finance
David Mammina is a partner and wealth advisor at Coastline Wealth Management, where he helps individuals and families navigate financial decisions with clarity, confidence, and purpose.
With more than 15 years of experience, he is known for his calm presence, collaborative mindset, and ability to make complex strategies feel simple and actionable. He is recognized for leadership in client-first financial planning and relationship-based advising.
Mammina works closely with clients experiencing pivotal life transitions – such as retirement, business succession, or legacy planning – bringing structure and alignment to their wealth and values. He also plays a key leadership role in shaping Coastline’s advisor development and business owner planning initiatives, mentoring rising advisors and helping the firm scale its impact.
His approach blends deep technical knowledge with genuine human connection, building relationships that span generations. Clients often describe him as steady, thoughtful, and fully invested in their success – qualities that define not just his work but his leadership style.
Outside the office, Mammina is a devoted husband, an avid sailor, and an active member of his local community. Whether at the helm of a boat or guiding a client through a significant financial decision, he leads with integrity, intention, and heart.
1303 Main Street, Port Jefferson, NY 11777
631 473 1188
dmammina@coastlinewealth.com
linkedin.com/in/davidmammina
coastlinewealth.com
David Mammina
Partner and CFP Wealth Advisor
Coastline Wealth Management
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Bio
Milestones
“I recognise the need to build a stronger brand presence online that differentiates us from the many other brokers and bankers in the market”
George Louca,
3LANE Finance
2007
2015–Present
2019–Present
2023
2025
Began his career in financial services
2007
2015: Joined Coastline Wealth Management
2015–Present: Developed firm-wide Financial Planning Program, co-developer of Coastline’s Strategic Planning Process for Business Owners
2015–
Present
2019: Named partner at Coastline Wealth Management
2019–Present: Core contributor to Coastline’s Advisor Development and Mentorship Program
2021: Co-developed strategic planning program for business owners
2019–
Present
Achieved PFP designation and entered the President’s Circle, recognizing top national performers
2023
Successfully mentored three advisors to independence and currently leading a team of emerging professionals
2025
Milestones
Milestones
Sept 2021
Feb 2022
Apr 2022
Jul 2022
Aug
2022
Suncorp Bank introduces Solar Home Bonus offer for customers who are choosing renewable energy for their homes
Sept 2021
Month-on-month market share growth commences
Feb 2022
Suncorp Bank wins the Canstar award for most outstanding value in investment loans
Apr 2022
Suncorp Bank wins Money Magazine’s Bank of the Year and Business Bank of the Year awards for the fifth year in a row
Jul 2022
Suncorp Bank’s turnaround times are the lowest they have ever been. The lender becomes Australia’s first certified carbon neutral bank for both its operation and transaction services
Aug 2022
Milestones
One of his most pressing challenges is incorporating a social media presence into the business, which has already been successful in terms of repeat business and referrals.
“I recognise the need to build a stronger brand presence online that differentiates us from the many other brokers and bankers in the market,” he adds. “My focus is on being more active on Instagram, Facebook and LinkedIn, which increases visibility and reinforces our position as a firm that consistently solves problems and delivers results.”
George approaches his work with passion and commitment and excels at solving problems, working closely with clients, and building something meaningful for them and the business.
A people person at heart, he finds satisfaction in making a difference. He often puts in long hours, not out of obligation, but because he cares about the work and the growth of 3LANE Finance.
However, it has been an intricate process to ensure his team are onboard with his vision. Kuhn places importance of explaining his targets and the blueprint to achieve them.
He adds, “The biggest challenge is getting everyone comfortable with the pace that I’m looking for to drive our buildout and growth. How I deal with it is by being open and transparent, and responsive to questions or concerns. This way, everything gets thoroughly discussed and resolved.”
With almost four decades in the industry, Kuhn has developed methods that have consistently delivered. It is why he has been tasked with so many leadership roles and he intends to maintain his focus on creating more success at Westfield Specialty.
“I think I am and have always tried to be methodical. I look at the big picture yet stay focused on executing the different opportunities or plans that I have in front of me. I don’t get emotional or make emotional decisions.”
Chief underwriting officer of executive risk at Chubb
President of financial insurance solutions at Kemper
Chief underwriting officer at Axis Capital
CEO of global Insurance at Endurance
CEO of global Insurance at Sompo International
George and his team attract and keep clients by delivering tangible results and personalising the process. Most of their work comes from referrals or repeat business, reinforcing that they are doing the right thing. He takes the time to understand what each client needs financially and emotionally and treats their challenges like his own.
“If we do our job well, there’s no reason for them to look elsewhere,” he adds. “Success is when we resolve a client’s issue, and they feel supported and genuinely happy with the outcome.”
He is most proud of building the brokerage from a one-person operation to a six-person team in 2025. That growth was never part of his original plan, but the company took on a life of its own thanks to strong demand, repeat business, and steady referrals.
“I see that growth as a direct reflection of the service we’ve delivered and the trust we’ve earned,” George reflects.
3LANE Finance is known for its expertise in securing commercial finance for various clients, including medical professionals, childcare operators, professional services firms, property investors and small business owners.
MPA named George Louca to its prestigious Top Commercial Brokers of 2025 list, recognising his standout performance by total commercial loan volume over FY24.
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