Thanks all I was playing around with various ways I end up trying
"It's a strange craft," Jaslyn said, splashing into the water to examine it. "It reminds me a bit of - uggh” jaslyn grunted as she heaved herself onboard “ that raft we made."
Does it sound to clunky ?
The sentence you've written isn't bad. It's really a question of style, and so the two things to worry about are that you are being consistent, and that you are being intentional about what you're doing.
For consistency, if you put that grunt in then you should also have other little utterances from other characters peppered through your dialogue.
In terms of intention, you're making a choice between realism and flow in your dialogue. For some stories you want a snappy, Whedon-esque flow to your dialogue that doesn't exist in real life. In other stories you want to be closer to real dialogue with all its Ums, Ahs, and Ers.
Make the choice that fits the tone you want the book to have, do you want it to be more or less formal? Do you want the characters to sound more 'folksy' or 'real', or do you want their conversations to be entertaining and smooth?