For ships that consume high volumes of fuel, need a readily available supply, store large amounts aboard and cannot necessarily bunker regularly, it is hard to see an alternative to LNG at present, LansdowneMoritz small-scale LNG and alternative fuels advisor Ed Glossop said.

"We fundamentally believe in LNG," Glossop said. "We also believe in the energy transition because in our lifetimes investment in LNG will decline," he added, suggesting that demand will continue until at least 2040.

He said there might be niches where electrification, hydrogen and ammonia can be used for shipping. "But for the large fuel-consuming segments, we can't really see past LNG at the moment."

LansdowneMoritz managing consultant Gary Regan admits that the record gas prices seen this year have prompted existing LNG-fuelled vessels to switch over to using oil products as a cheaper alternative.

It has also led companies, who bought their LNG bunker volumes on a spot price basis in a market that looked oversupplied and those contracting supply today, to look at buying on an oil-indexed basis.

He sees the high gas prices as "a medium phenomenon".

"In the long-term, LNG will be at a discount to oil," Regan said. "We are just in a tight market at the moment. But you do have to hold your nerve."

Looking further ahead, Glossop said there is a need to understand what the LNG pathway looks like, whether it will move into bio and synthetic forms and how LNG infrastructure could be repurposed for ammonia or other fuels in the future.

He gives the example of future-proofing LNG bunker vessel designs so they can be adapted for future fuels.

Understanding what we have learned from LNG-fuelled ships and how that can be applied to other alternative fuels is an important part of the transition, he said.